Title: Bona Fide Plant Steroid Receptors Are Innovated in Seed Plants and Angiosperms through Successive Whole Genome Duplication Events.

Whole genome duplication (WGD) events are widespread in plants and animals, thus their long-term evolutionary contribution has long been speculated, yet a specific contribution is difficult to verify. Here, we show that ɛ-WGD and ζ-WGD contribute to the origin and evolution of bona fide brassinosteroid (BR) signaling through the innovation of active BR biosynthetic enzymes and active BR receptors from their respective ancestors. We found that BR receptors BRI1 (BR Insensitive 1) and BRL1/3 (BRI1-likes 1/3) derived by ɛ-WGD and ζ-WGD, which occurred in the common ancestor of angiosperms and seed plants, respectively, while orphan BR receptor BRL2 first appeared in stomatophytes. Additionally, CYP85A enzymes synthesizing the bioactive BRs derived from a common ancestor of seed plants while its sister enzymes CYP90 synthesizing BR precursors presented in all land plants, implying possible ligand-receptor coevolution. Consistently, the island domains (IDs) responsible for BR perception in BR receptors were most divergent among different receptor branches, supporting ligand-driven evolution. As a result, BRI1 was the most diversified BR receptor in angiosperms. Importantly, relative to the BR biosynthetic DET2 gene presented in all land plants, BRL2, BRL1/3 and BRI1 had high expression in vascular plants ferns, gymnosperms and angiosperms, respectively. Notably, BRI1 is the most diversified BR receptor with the most abundant expression in angiosperms, suggesting potential positive selection. Therefore, WGDs initiate a neofunctionalization process diverged by ligand-perception and transcriptional expression, which might optimize both BR biosynthetic enzymes and BR receptors, likely contributing to the evolution of land plants, especially seed plants and angiosperms.

Kinase regulators evolved into two families by gain and loss of ability to bind plant steroid receptors.

All biological functions evolve by fixing beneficial mutations and removing deleterious ones. Therefore, continuously fixing and removing the same essential function to separately diverge monophyletic gene families sounds improbable. Yet, here we report that brassinosteroid insensitive1 kinase inhibitor1 (BKI1)/membrane-associated kinase regulators (MAKRs) regulating a diverse function evolved into BKI1 and MAKR families from a common ancestor by respectively enhancing and losing ability to bind brassinosteroid receptor brassinosteroid insensitive1 (BRI1). The BKI1 family includes BKI1, MAKR1/BKI1-like (BKL) 1, and BKL2, while the MAKR family contains MAKR2-6. Seedless plants contain only BKL2. In seed plants, MAKR1/BKL1 and MAKR3, duplicates of BKL2, gained and lost the ability to bind BRI1, respectively. In angiosperms, BKL2 lost the ability to bind BRI1 to generate MAKR2, while BKI1 and MAKR6 were duplicates of MAKR1/BKL1 and MAKR3, respectively. In dicots, MAKR4 and MAKR5 were duplicates of MAKR3 and MAKR2, respectively. Importantly, BKI1 localized in the plasma membrane, but BKL2 localized to the nuclei while MAKR1/BKL1 localized throughout the whole cell. Importantly, BKI1 strongly and MAKR1/BKL1 weakly inhibited plant growth, but BKL2 and the MAKR family did not inhibit plant growth. Functional study of the chimeras of their N- and C-termini showed that only the BKI1 family was partially reconstructable, supporting stepwise evolution by a seesaw mechanism between their C- and N-termini to alternately gain an ability to bind and inhibit BRI1, respectively. Nevertheless, the C-terminal BRI1-interacting motif best defines the divergence of BKI1/MAKRs. Therefore, BKI1 and MAKR families evolved by gradually gaining and losing the same function, respectively, extremizing divergent evolution and adding insights into gene (BKI1/MAKR) duplication and divergence.

Bradykinin-(1-9) mitigates autophagy through upregulating PI3K/Akt in rats with myocardial infarction.

The cardioprotective mechanisms of bradykinin-(1-9) in myocardial infarction were unclear. We investigated the effect of bradykinin-(1-9) on cardiac function, fibrosis, and autophagy induced by myocardial infarction and identified the mechanisms involved. To investigate the cardioprotective effect of bradykinin-(1-9), various doses of bradykinin-(1-9), its B2 receptor blocker HOE140, or their combination were administered to rats via subcutaneous osmotic minipump implantation before myocardial infarction. After 2 days, myocardial infarction was induced by ligation of the left anterior descending coronary artery. After 2 weeks, echocardiographic measurements and euthanasia were performed. Bradykinin-(1-9) treatment attenuated left ventricular dysfunction, fibrosis, and autophagy in rats with myocardial infarction, which was partially reversed by HOE140 administration. Moreover, the downregulatory effect of bradykinin-(1-9) on autophagy was partially reversed by combination with the PI3K inhibitor LY294002. Thus, bradykinin-(1-9) inhibits myocardial infarction-induced cardiomyocyte autophagy by upregulating the PI3K/Akt pathway.

Tracing the future of epidemics: Coincident niche distribution of host animals and disease incidence revealed climate-correlated risk shifts of main zoonotic diseases in China.

Climate has critical roles in the origin, pathogenesis and transmission of infectious zoonotic diseases. However, large-scale epidemiologic trend and specific response pattern of zoonotic diseases under future climate scenarios are poorly understood. Here, we projected the distribution shifts of transmission risks of main zoonotic diseases under climate change in China. First, we shaped the global habitat distribution of main host animals for three representative zoonotic diseases (2, 6, and 12 hosts for dengue, hemorrhagic fever, and plague, respectively) with 253,049 occurrence records using maximum entropy (Maxent) modeling. Meanwhile, we predicted the risk distribution of the above three diseases with 197,098 disease incidence records from 2004 to 2017 in China using an integrated Maxent modeling approach. The comparative analysis showed that there exist highly coincident niche distributions between habitat distribution of hosts and risk distribution of diseases, indicating that the integrated Maxent modeling is accurate and effective for predicting the potential risk of zoonotic diseases. On this basis, we further projected the current and future transmission risks of 11 main zoonotic diseases under four representative concentration pathways (RCPs) (RCP2.6, RCP4.5, RCP6.0, and RCP8.5) in 2050 and 2070 in China using the above integrated Maxent modeling with 1,001,416 disease incidence records. We found that Central China, Southeast China, and South China are concentrated regions with high transmission risks for main zoonotic diseases. More specifically, zoonotic diseases had diverse shift patterns of transmission risks including increase, decrease, and unstable. Further correlation analysis indicated that these patterns of shifts were highly correlated with global warming and precipitation increase. Our results revealed how specific zoonotic diseases respond in a changing climate, thereby calling for effective administration and prevention strategies. Furthermore, these results will shed light on guiding future epidemiologic prediction of emerging infectious diseases under global climate change.

Pan-brassinosteroid signaling revealed by functional analysis of NILR1 in land plants.

Brassinosteroid (BR) signaling has been identified from the ligand BRs sensed by the receptor Brassinosteroid Insensitive 1 (BRI1) to the final activation of Brassinozole Resistant 1/bri1 EMS-Suppressor 1 through a series of transduction events. Extensive studies have been conducted to characterize the role of BR signaling in various biological processes. Our previous study has shown that Excess Microsporocytes 1 (EMS1) and BRI1 control different aspects of plant growth and development via conserved intracellular signaling. Here, we reveal that another receptor, NILR1, can complement the bri1 mutant in the absence of BRs, indicating a pathway that resembles BR signaling activated by NILR1. Genetic analysis confirms the intracellular domains of NILR1, BRI1 and EMS1 have a common signal output. Furthermore, we demonstrate that NILR1 and BRI1 share the coreceptor BRI1 Associated Kinase 1 and substrate BSKs. Notably, the NILR1-mediated downstream pathway is conserved across land plants. In summary, we provide evidence for the signaling cascade of NILR1, suggesting pan-brassinosteroid signaling initiated by a group of distant receptor-ligand pairs in land plants.

The Role of SBI2/ALG12/EBS4 in the Regulation of Endoplasmic Reticulum-Associated Degradation (ERAD) Studied by a Null Allele.

Redundancy and lethality is a long-standing problem in genetics but generating minimal and lethal phenotypes in the knockouts of the same gene by different approaches drives this problem to a new high. In Asn (N)-linked glycosylation, a complex and ubiquitous cotranslational and post-translational protein modification required for the transfer of correctly folded proteins and endoplasmic reticulum-associated degradation (ERAD) of misfolded proteins, ALG12 (EBS4) is an α 1, 6-mannosyltransferase catalyzing a mannose into Glc3Man9GlcNAc2. In Arabidopsis, T-DNA knockout alg12-T is lethal while likely ebs4 null mutants isolated by forward genetics are most healthy as weak alleles, perplexing researchers and demanding further investigations. Here, we isolated a true null allele, sbi2, with the W258Stop mutation in ALG12/EBS4. sbi2 restored the sensitivity of brassinosteroid receptor mutants bri1-5, bri1-9, and bri1-235 with ER-trapped BRI1 to brassinosteroids. Furthermore, sbi2 maturated earlier than the wild-type. Moreover, concomitant with impaired and misfolded proteins accumulated in the ER, sbi2 had higher sensitivity to tunicamycin and salt than the wild-type. Our findings thus clarify the role of SBI2/ALG12/EBS4 in the regulation of the ERAD of misfolded glycoproteins, and plant growth and stress response. Further, our study advocates the necessity and importance of using multiple approaches to validate genetics study.

Engineering Chimeras by Fusing Plant Receptor-like Kinase EMS1 and BRI1 Reveals the Two Receptors' Structural Specificity and Molecular Mechanisms.

Brassinosteriods (BRs) are plant hormones essential for plant growth and development. The receptor-like kinase (RLK) BRI1 perceives BRs to initiate a well-known transduction pathway which finally activate the transcription factors BZR1/BES1 specifically regulating BR-mediated gene expression. The RLK EMS1 governs tapetum formation via the same signaling pathway shared with BRI1. BRI1 and EMS1 have a common signal output, but the gene structural specificity and the molecular response remain unclear. In this study, we identified that the transmembrane (TM), intracellular juxtamembrane (iJM), kinase, and leucin-rich repeats 1-13 (LRR1-13) domains of EMS1 could replace the corresponding BRI1 domain to maintain the BR receptor function, whereas the extracellular juxtamembrane (eJM) and LRR1-14 domains could not, indicating that the LRR14-EJM domain conferred functional specificity to BRI1. We compared the kinase domains of EMS1 and BRI1, and found that EMS1's kinase activity was weaker than BRI1's. Further investigation of the specific phosphorylation sites in BRI1 and EMS1 revealed that the Y1052 site in the kinase domain was essential for the BRI1 biological function, but the corresponding site in EMS1 showed no effect on the biological function of EMS1, suggesting a site regulation difference in the two receptors. Furthermore, we showed that EMS1 shared the substrate BSKs with BRI1. Our study provides insight into the structural specificity and molecular mechanism of BRI1 and EMS1, as well as the origin and divergence of BR receptors.

Brassinosteroids synthesised by CYP85A/A1 but not CYP85A2 function via a BRI1-like receptor but not via BRI1 in Picea abies.

Brassinosteroids (BRs) are essential plant hormones. In angiosperms, brassinolide and castasterone, the first and second most active BRs, respectively, are synthesised by CYP85A2 and CYP85A/A1, respectively. BRs in angiosperms function through an essential receptor, BR Insensitive 1 (BRI1). In addition, some angiosperms also have non-essential BRI1-like 1/3 (BRL1/3). In conifers, BRs promote seed germination under drought stress; however, how BRs function in gymnosperms is unknown. In this study, we performed functional complementation of BR biosynthesis and receptor genes from Picea abies with respective Arabidopsis mutants. We found that P. abies possessed functional PaCYP85A and PaBRL1 but not PaCYP85A2 or PaBRI1, and this results in weak BR signaling, and both PaCYP85A and PaBRL1 were abundantly expressed. However, neither BR treatment of P. abies seedlings nor expression of PaBRL1 in the Arabidopsis Atbri1 mutant promoted plant height, despite the fact that BR-responsive genes were activated. Importantly, chimeric AtBRI1 replaced with the BR-binding domain of PaBRL1 complemented the Atbri1 phenotypes. Furthermore, PaBRL1 had less kinase activity than BRI1 in vitro. Overall, P. abies had weak but still active BR signaling, explaining aspects of its slow growth and high stress tolerance. Our study sheds light on the functional and evolutionary significance of distinct BR signaling that is independent of BRI1 and brassinolide.

Puerarin plays a protective role in chondrocytes by activating Beclin1-dependent autophagy.

Puerarin can protect chondrocytes, whereby ameliorating osteoarthritis. Puerarin also promotes autophagy. Autophagy maintains chondrocyte homeostasis. The role of autophagy in puerarin-protected chondrocytes is unknown. Puerarin promoted chondrocyte autophagy. Puerarin-protected chondrocytes were reversed by autophagy inhibitors and Beclin1 inhibitor. 3-MA or Beclin1 inhibitor in vivo reversed puerarin-ameliorated cartilage damage of osteoarthritis mice. Thus, puerarin can protect chondrocytes through Beclin1-dependent autophagy activation.

Comparative analysis of the diagnostic value of several methods for the diagnosis of patent foramen ovale.

The aim of this research was to compare the sensitivity and positive predictive value of contrast transcranial Doppler (c-TCD), contrast transthoracic echocardiography (c-TTE), and contrast transesophageal echocardiography (c-TEE), to determine the best method for diagnosing patent foramen ovale (PFO) and to provide a reference for the further improvement of clinical practice. We investigated 161 patients who suffered from migraines, cryptogenic stroke, TIA, and cerebral infarction of unknown cause. All patients underwent transcatheter examination, and the results of the right heart catheterization (RHC) were considered the gold standard for PFO diagnosis. The present study revealed that c-TTE with the Valsalva maneuver had a higher sensitivity in detecting PFO related right-to-left shunt (PFO-RLS), c-TCD performed similarly to c-TEE but maybe produce more false positives. Moreover, when we observed color shunt from the slit-like channel between the septum primum and the septum secundum on TEE, the positive predictive value was the highest. Patients with suspected PFO should be examined with c-TTE and c-TEE for confirmation. When there were a large number of bubbles in the left heart, especially in the presence of color shunt, the positive predictive value was the highest. The positive results of c-TCD only point out the presence of right-to-left shunt and cannot exclude extracardiac shunt, so c-TCD should not be used as a screen for PFO, additional measures such as c-TTE and c-TEE should be used.

Growth years and post-harvest processing methods have critical roles on the contents of medicinal active ingredients of Scutellaria baicalensis.

Optimizing the processing technology is an effective way to improve the yield of active ingredients for the industrial production of medicinal crops. Baikal Skullcap (Scutellaria baicalensis Georgi) is a perennial herb in the Lamiaceae family and its dried root is used as a famous traditional Chinese medicine (TCM). Modern pharmacological studies have shown that the active ingredients of S. baicalensis have important pharmacological effects including anti-oxidation, anti-bacterial, anti-viral, anti-tumor, and anti-inflammation. Specifically, it is recently found that S. baicalensis has significant curative effects on the treatment of corona virus disease 2019 (COVID-19). In recent years, the market demand for the medicinal products of S. baicalensis is increasing because of its great medicinal values. However, the annual yield of active ingredients originated from the root of S. baicalensis is limited due to that little progress has been made on the traditional processing technology used in the extraction process. A pressing issue faced by both herbalists and scientists is how to improve the processing efficiency, thereby obtaining the maximum yield of products for S. baicalensis. In this study, a systematic analysis on the effects of growth years and post-harvest processing on the contents of medicinal active ingredients of S. baicalensis was conducted. The contents of eight active ingredients (baicalin, wogonoside, baicalein, wogonin, scutellarin, scutellarein, apigenin, and chrysin) in roots of S. baicalensis of different growth years (ranging from 1 year to 15 years) were estimated using high performance liquid chromatography (HPLC) and further analyzed to determine the optimal harvest period. In particular, the contents of six active ingredients in different parts (cortex and stele) of the root of S. baicalensis were estimated and compared. Meanwhile, the dynamic changes of the contents of active ingredients in fresh-crush and fresh-cut roots of S. baicalensis at room temperature were compared and analyzed to reveal the influence of post-harvest treatment on the contents of active ingredients. In addition, the effects of six different post-harvest treatments on the contents of active ingredients were systematically designed and compared to determine the best primary processing technology. The results showed that the best harvesting period for S. baicalensis should be determined as 2-3 years based on comprehensive evaluation of active ingredient content, annual yield increment, and land use efficiency. The contents of active ingredients including baicalin, wogonoside, baicalein, and wogonin in cortex were significantly higher than those in stele (P ≤  0.05). The contents of baicalin, wogonoside, and scutellarin in fresh roots of S. baicalensis significantly reduced as the storage time increased, but the reduction of fresh-cutting was significantly lower than that of fresh-crushing. For the effects of different processing treatments, the contents of four main active ingredients (baicalin, wogonoside, baicalein, and wogonin) under drying (D) and cutting-drying (C-D) treatments were significantly higher than those of the other four treatments (P ≤  0.05). Collectively, the above results will not only provide novel processing methods that will improve the yield of active ingredients for S. baicalensis, but also shed light on the optimization of processing technology for the industrial production of medicinal crops.

Effects of drought stress on hybrids of Vigna radiata at germination stage.

Drought is one the critical abiotic factors that reduces the germination, growth and yield of crops. Therefore the present project was designed with the objective to screen the best drought tolerant hybrid of Vigna radiata. Genetic variations for drought tolerance among these hybrids were assessed by simple and efficient technique. Seven hybrids of V. radiata (9801, 7002, 9706, 08003, 07007, 97012 and 08007) were used for screening against three levels of drought stress (zero, control), 5% (-0.05 MPa) and 10% (-0.1 MPa) induced by Polyethyleneglycol (PEG6000). A higher proline content was observed in 07007 (6.10 µg/g fresh weight) as compared to all other hybrids. Treated seedlings of each hybrid were compared with their respective control to evaluate the differences in their growth under drought. Different parameters such as percentage of germination, germination stress tolerance index (GSI), shoot and root weights (bath fresh and dry) and lengths, root length stress index (RLSI), dry matter stress index (DMSI) and plant height stress index (PHSI) showed considerable variations. Germination percentage, shoot weights, PHSI and DMSI decreased in all hybrids along with the increase of PEG induced drought stress (5% and 10% PEG). In contrary, root weights and RLSI were increased under drought. Overall 07007 showed a better performance, and can therefore be classified as a drought tolerant hybrid.

Angiotensin-(1-7) Suppresses Hepatocellular Carcinoma Growth and Angiogenesis via Complex Interactions of Angiotensin II Type 1 Receptor, Angiotensin II Type 2 Receptor and Mas Receptor.

We recently confirmed that angiotensin II (Ang II) type 1 receptor (AT1R) was overexpressed in hepatocellular carcinoma tissue using a murine hepatoma model. Angiotensin(Ang)-(1-7) has been found beneficial in ameliorating lung cancer and prostate cancer. Which receptor of Ang-(1-7) is activated to mediate its effects is much speculated. This study was designed to investigate the effects of Ang-(1-7) on hepatocellular carcinoma, as well as the probable mechanisms. H22 hepatoma-bearing mice were randomly divided into five groups for treatment: mock group, low-dose Ang-(1-7), high-dose Ang-(1-7), high-dose Ang-(1-7) + A779 and high-dose Ang-(1-7) + PD123319. Ang-(1-7) treatment inhibited tumor growth time- and dose-dependently by arresting tumor proliferation and promoting tumor apoptosis as well as inhibiting tumor angiogenesis. The effects of Ang-(1-7) on tumor proliferation and apoptosis were reversed by coadministration with A779 or PD123319, whereas the effects on tumor angiogenesis were completely reversed by A779 but not by PD123319. Moreover, Ang-(1-7) downregulated AT1R mRNA, upregulated mRNA levels of Ang II type 2 receptor (AT2R) and Mas receptor (MasR) and p38-MAPK phosphorylation and suppressed H22 cell-endothelial cell communication. Thus, Ang-(1-7) administration suppresses hepatocellular carcinoma via complex interactions of AT1R, AT2R and MasR and may provide a novel and promising approach for the treatment of hepatocellular carcinoma.

Risk factors for long-term outcome of drug-eluting stenting in adults with early-onset coronary artery disease.

OBJECTIVE: We lack data on the long-term outcome of drug-eluting stenting in patients with early-onset coronary artery disease (CAD). Here, we investigated the association of traditional risk factors and major adverse cardiovascular events (MACEs) after drug-eluting stenting in patients with CAD who were < 50 years old. METHODS: We enrolled 437 consecutive CAD patients < 50 years old who underwent drug-eluting stenting and 132 subjects who were age- and sex-matched and angiographically shown to be disease free as controls. MACEs were analyzed in CAD patients for a median of 24 months [interquartile range 14-34 months]. RESULTS: Male patients accounted for 90.4% of cases. As compared with controls, patients with early-onset CAD had higher body mass index and rates of smoking, family history of CAD, and diabetes and hypercholesterolemia. During the hospital stay, 1 patient died, and the incidence of MACEs was 1.1%. At the end of follow-up, the overall death rate was 0.7%. MACEs were observed in 54 patients (12.4%). On Cox proportional hazard analyses, positive family history and diabetes were independent risk factors of MACEs (HR 2.61, 95% confidence interval 1.29-4.00, p = 0.002; and HR 2.48, 95% confidence interval 0.86-3.14, p = 0.004, respectively). CONCLUSIONS: Drug-eluting stenting is a reliable treatment for patients with early-onset CAD. Positive family history of CAD and diabetes are independent risk factors of adverse cardiovascular events in this subgroup of patients after drug-eluting stent implantation.

The receptor-like kinase EMS1 and BRI1 coordinately regulate stamen elongation via the transcription factors BES1/BZR1 in Arabidopsis.

Plants possess a large family of receptor kinase proteins to mediate cell-to-cell and cell-to-environment communication, and these regulations are essential for plant growth and development as well as resistance to biotic or abiotic stresses. EMS1 is a receptor kinase which involved in tapetum cell fate determination during anther development, while brassinosteroid (BR) receptor, BRI1, controls most aspects of plant growth and development. Although EMS1 and BRI1 are known to regulate independent biological processes, they interact with identical components of the downstream signaling pathways. However, the biological processes other than the tapetum development controlled by the EMS1 signal are not clear. Here, we report that EMS1 signaling-related mutants exhibited an insufficient stamen elongation phenotype, similar to BR signaling mutants. Transgenic expression of BRI1 restored the short filament phenotype of ems1. Conversely, co-expression of EMS1 and TPD1 also restored the short filaments of BRI1 mutants, bri1. Genetic experiments confirmed that EMS1 and BRI1 regulate filament elongation through their downstream transcription factors BES1/BZR1. Molecular analysis suggested that the decrease in BR signaling output in filaments of the ems1 mutant caused deficient filament development. Moreover, in vitro and in vivo experiments proved BES1 interacts with filament-specific transcription factor MYB21. Together, we found that the two receptor-like kinases (RLKs) EMS1 and BRI1 are cooperatively involved in the regulation of filament elongation via the transcription factors BES1/BZR1. These results indicated that the biological processes regulated by EMS1 and BRI1 in plants are both independent and interactive, which provides us with insights into multidimensional molecular control of the RLK pathway.

Heterogeneous virulence of pandemic 2009 influenza H1N1 virus in mice.

BACKGROUND: Understanding the pathogenesis of influenza infection is a key factor leading to the prevention and control of future outbreaks. Pandemic 2009 Influenza H1N1 infection, although frequently mild, led to a severe and fatal form of disease in certain cases that make its virulence nature debatable. Much effort has been made toward explaining the determinants of disease severity; however, no absolute reason has been established. RESULTS: This study presents the heterogeneous virulence of clinically similar strains of pandemic 2009 influenza virus in human alveolar adenocarcinoma cells and mice. The viruses were obtained from patients who were admitted in a local hospital in China with a similar course of infection and recovered. The A/Nanchang/8002/2009 and A/Nanchang/8011/2009 viruses showed efficient replication and high lethality in mice while infection with A/Nanchang/8008/2009 was not lethal with impaired viral replication, minimal pathology and modest proinflammatory activity in lungs. Sequence analysis displayed prominent differences between polymerase subunits (PB2 and PA) of viral genomes that might correlate with their different phenotypic behavior. CONCLUSIONS: The study confirms that biological heterogeneity, linked with the extent of viral replication, exists among pandemic H1N1 strains that may serve as a benchmark for future investigations on influenza pathogenesis.

Future landscape of renewable fuel resources: Current and future conservation and utilization of main biofuel crops in China.

Biofuel crops are one of the most promising regenerative alternatives of energy resources to fossil fuels. Revealing the current and future resource distribution patterns of biofuel crops will promote the development of green energies and the mitigation of greenhouse gas emissions. In this study, we first conducted a comprehensive and systematic analysis on the distribution patterns of main biofuel crops in China, using 22,352 occurrence records of 31 biofuel plant species and thirty-year environmental variables (1970-2000) with maximum entropy modeling, as well as nine-year field investigation of land use (2011-2019). The results showed that there were six different sub-regions for main biofuel crops in China, while Southwest China and South China were determined as the main concentrated potential regions. Specifically, the ranges of these regions were wider than those of current land use of main biofuel crops in China, indicating great potential for industrial cultivation. Moreover, the main biofuel crops had diverse changing patterns including increase, decrease and unstable under future climate change. Among them, biofuel crops with increase pattern (six crops) and decrease pattern (seven crops) should receive high attention for future resource utilization and production. Further field validation results confirmed that the above distribution patterns were mainly determined by increasing global temperature and precipitation. Collectively, these results will provide valuable references for the utilization and development of main biofuel resources under climate change in China, thereby shedding light on studies regarding the production of green biofuels globally.

A Non-redundant Function of MNS5: A Class I α-1, 2 Mannosidase, in the Regulation of Endoplasmic Reticulum-Associated Degradation of Misfolded Glycoproteins.

Endoplasmic Reticulum-Associated Degradation (ERAD) is one of the major processes in maintaining protein homeostasis. Class I α-mannosidases MNS4 and MNS5 are involved in the degradation of misfolded variants of the heavily glycosylated proteins, playing an important role for glycan-dependent ERAD in planta. MNS4 and MNS5 reportedly have functional redundancy, meaning that only the loss of both MNS4 and MNS5 shows phenotypes. However, MNS4 is a membrane-associated protein while MNS5 is a soluble protein, and both can localize to the endoplasmic reticulum (ER). Furthermore, MNS4 and MNS5 differentially demannosylate the glycoprotein substrates. Importantly, we found that their gene expression patterns are complemented rather than overlapped. This raises the question of whether they indeed work redundantly, warranting a further investigation. Here, we conducted an exhaustive genetic screen for a suppressor of the bri1-5, a brassinosteroid (BR) receptor mutant with its receptor downregulated by ERAD, and isolated sbi3, a suppressor of bri1-5 mutant named after sbi1 (suppressor of bri1). After genetic mapping together with whole-genome re-sequencing, we identified a point mutation G343E in AT1G27520 (MNS5) in sbi3. Genetic complementation experiments confirmed that sbi3 was a loss-of-function allele of MNS5. In addition, sbi3 suppressed the dwarf phenotype of bri1-235 in the proteasome-independent ERAD pathway and bri1-9 in the proteasome-dependent ERAD pathway. Importantly, sbi3 could only affect BRI1/bri1 with kinase activities such that it restored BR-sensitivities of bri1-5, bri1-9, and bri1-235 but not null bri1. Furthermore, sbi3 was less tolerant to tunicamycin and salt than the wild-type plants. Thus, our study uncovers a non-redundant function of MNS5 in the regulation of ERAD as well as plant growth and ER stress response, highlighting a need of the traditional forward genetic approach to complement the T-DNA or CRISPR-Cas9 systems on gene functional study.

Kinase Function of Brassinosteroid Receptor Specified by Two Allosterically Regulated Subdomains.

Plants acquire the ability to adapt to the environment using transmembrane receptor-like kinases (RLKs) to sense the challenges from their surroundings and respond appropriately. RLKs perceive a variety of ligands through their variable extracellular domains (ECDs) that activate the highly conserved intracellular kinase domains (KDs) to control distinct biological functions through a well-developed downstream signaling cascade. A new study has emerged that brassinosteroid-insensitive 1 (BRI1) family and excess microsporocytes 1 (EMS1) but not GASSHO1 (GSO1) and other RLKs control distinct biological functions through the same signaling pathway, raising a question how the signaling pathway represented by BRI1 is specified. Here, we confirm that BRI1-KD is not functionally replaceable by GSO1-KD since the chimeric BRI1-GSO1 cannot rescue bri1 mutants. We then identify two subdomains S1 and S2. BRI1 with its S1 and S2 substituted by that of GSO1 cannot rescue bri1 mutants. Conversely, chimeric BRI1-GSO1 with its S1 and S2 substituted by that of BRI1 can rescue bri1 mutants, suggesting that S1 and S2 are the sufficient requirements to specify the signaling function of BRI1. Consequently, all the other subdomains in the KD of BRI1 are functionally replaceable by that of GSO1 although the in vitro kinase activities vary after replacements, suggesting their functional robustness and mutational plasticity with diverse kinase activity. Interestingly, S1 contains αC-ß4 loop as an allosteric hotspot and S2 includes kinase activation loop, proposedly regulating kinase activities. Further analysis reveals that this specific function requires ß4 and ß5 in addition to αC-ß4 loop in S1. We, therefore, suggest that BRI1 specifies its kinase function through an allosteric regulation of these two subdomains to control its distinct biological functions, providing a new insight into the kinase evolution.

[Methods on construction of core germplasm collection of Scutellaria baicalensis by ISSR marker].

OBJECTIVE: To build up primary core germplasm of Scutellaria baicalensis. METHODS: The genetic diversity of 40 germplasm resources of Scutellaria baicalensis in different province were analyzed by ISSR, and the primary core germplasm were constructed with progressive sampling method of smallest genetic distance. RESULTS: 15 primers, which showed good repetitive, special bands and distinct polymorphism, were selected from 51 random ISSR primers. Then the total 248 loci were amplified by these selected 15 primers, with a 97.17% polymorphic loci. The average of Shannon information index (I), Nei's genetic diversity (H), number of alleles and effective number of alleles (NE) by POPGENE 32 analysis were 0.4353, 0.2819, 1.9640 and 1.4617, respectively. It showed there was highly genetic diversity in the 40 germplasm resources. The result of analysis by NTSYS-PC software shows the genetic similarity (Gs) were among 0.64 and 0.80, and there was upper coherence between the clustering result and source core germplasm collection except individual germplasms. The result showed the percentage of polymorphic loci was obviously reduced and the Shannon's information index and Nei's genetic diversity were increased a little, but the index change of germplasm genetic diversity was less than that before sampling. The core germplasms from No. 3 sampling were most representative, whose sampling number was about 30% of the initial sampling, and the percentage of polymorphic loci was that of before sampling 96.8%. CONCLUSIONS: It was practicable that the methods would be used to construct core germplasm collection of Scutellaria baicalensis by ISSR marker.