INDUCER OF CBF EXPRESSION 1 promotes cold-enhanced immunity by directly activating salicylic acid signaling.

Cold stress affects plant immune responses, and this process may involve the salicylic acid (SA) signaling pathway. However, the underlying mechanism by which low-temperature signals coordinate with SA signaling to regulate plant immunity remains unclear. Here, we found that low temperatures enhanced the disease resistance of Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000. This process required INDUCER OF CBF EXPRESSION 1 (ICE1), the core transcription factor in cold-signal cascades. ICE1 physically interacted with NONEXPRESSER OF PATHOGENESIS-RELATED GENES 1 (NPR1), the master regulator of the SA signaling pathway. Enrichment of ICE1 on the PATHOGENESIS-RELATED GENE 1 (PR1) promoter and its ability to transcriptionally activate PR1 were enhanced by NPR1. Further analyses revealed that cold stress signals cooperate with SA signals to facilitate plant immunity against pathogen attack in an ICE1-dependent manner. Cold treatment promoted interactions of NPR1 and TGACG-BINDING FACTOR 3 (TGA3) with ICE1 and increased the ability of the ICE1-TGA3 complex to transcriptionally activate PR1. Together, our results characterize a critical role of ICE1 as an indispensable regulatory node linking low-temperature-activated and SA-regulated immunity. Understanding this crucial role of ICE1 in coordinating multiple signals associated with immunity broadens our understanding of plant-pathogen interactions.

Auxin contributes to jasmonate-mediated regulation of abscisic acid signaling during seed germination in Arabidopsis.

Abscisic acid (ABA) represses seed germination and postgerminative growth in Arabidopsis thaliana. Auxin and jasmonic acid (JA) stimulate ABA function; however, the possible synergistic effects of auxin and JA on ABA signaling and the underlying molecular mechanisms remain elusive. Here, we show that exogenous auxin works synergistically with JA to enhance the ABA-induced delay of seed germination. Auxin biosynthesis, perception, and signaling are crucial for JA-promoted ABA responses. The auxin-dependent transcription factors AUXIN RESPONSE FACTOR10 (ARF10) and ARF16 interact with JASMONATE ZIM-DOMAIN (JAZ) repressors of JA signaling. ARF10 and ARF16 positively mediate JA-increased ABA responses, and overaccumulation of ARF16 partially restores the hyposensitive phenotype of JAZ-accumulating plants defective in JA signaling in response to combined ABA and JA treatment. Furthermore, ARF10 and ARF16 physically associate with ABSCISIC ACID INSENSITIVE5 (ABI5), a critical regulator of ABA signaling, and the ability of ARF16 to stimulate JA-mediated ABA responses is mainly dependent on ABI5. ARF10 and ARF16 activate the transcriptional function of ABI5, whereas JAZ repressors antagonize their effects. Collectively, our results demonstrate that auxin contributes to the synergetic modulation of JA on ABA signaling, and explain the mechanism by which ARF10/16 coordinate with JAZ and ABI5 to integrate the auxin, JA, and ABA signaling pathways.

CO interacts with JAZ repressors and bHLH subgroup IIId factors to negatively regulate jasmonate signaling in Arabidopsis seedlings.

CONSTANS (CO) is a master flowering-time regulator that integrates photoperiodic and circadian signals in Arabidopsis thaliana. CO is expressed in multiple tissues, including young leaves and seedling roots, but little is known about the roles and underlying mechanisms of CO in mediating physiological responses other than flowering. Here, we show that CO expression is responsive to jasmonate. CO negatively modulated jasmonate-imposed root-growth inhibition and anthocyanin accumulation. Seedlings from co mutants were more sensitive to jasmonate, whereas overexpression of CO resulted in plants with reduced sensitivity to jasmonate. Moreover, CO mediated the diurnal gating of several jasmonate-responsive genes under long-day conditions. We demonstrate that CO interacts with JASMONATE ZIM-DOMAIN (JAZ) repressors of jasmonate signaling. Genetic analyses indicated that CO functions in a CORONATINE INSENSITIVE1 (COI1)-dependent manner to modulate jasmonate responses. Furthermore, CO physically associated with the basic helix-loop-helix (bHLH) subgroup IIId transcription factors bHLH3 and bHLH17. CO acted cooperatively with bHLH17 in suppressing jasmonate signaling, but JAZ proteins interfered with their transcriptional functions and physical interaction. Collectively, our results reveal the crucial regulatory effects of CO on mediating jasmonate responses and explain the mechanism by which CO works together with JAZ and bHLH subgroup IIId factors to fine-tune jasmonate signaling.

PHOSPHATE STARVATION RESPONSE1 (PHR1) interacts with JASMONATE ZIM-DOMAIN (JAZ) and MYC2 to modulate phosphate deficiency-induced jasmonate signaling in Arabidopsis.

Phosphorus (P) is a macronutrient necessary for plant growth and development. Inorganic phosphate (Pi) deficiency modulates the signaling pathway of the phytohormone jasmonate in Arabidopsis thaliana, but the underlying molecular mechanism currently remains elusive. Here, we confirmed that jasmonate signaling was enhanced under low Pi conditions, and the CORONATINE INSENSITIVE1 (COI1)-mediated pathway is critical for this process. A mechanistic investigation revealed that several JASMONATE ZIM-DOMAIN (JAZ) repressors physically interacted with the Pi signaling-related core transcription factors PHOSPHATE STARVATION RESPONSE1 (PHR1), PHR1-LIKE2 (PHL2), and PHL3. Phenotypic analyses showed that PHR1 and its homologs positively regulated jasmonate-induced anthocyanin accumulation and root growth inhibition. PHR1 stimulated the expression of several jasmonate-responsive genes, whereas JAZ proteins interfered with its transcriptional function. Furthermore, PHR1 physically associated with the basic helix-loop-helix (bHLH) transcription factors MYC2, MYC3, and MYC4. Genetic analyses and biochemical assays indicated that PHR1 and MYC2 synergistically increased the transcription of downstream jasmonate-responsive genes and enhanced the responses to jasmonate. Collectively, our study reveals the crucial regulatory roles of PHR1 in modulating jasmonate responses and provides a mechanistic understanding of how PHR1 functions together with JAZ and MYC2 to maintain the appropriate level of jasmonate signaling under conditions of Pi deficiency.

CONSTANS interacts with and antagonizes ABF transcription factors during salt stress under long-day conditions.

CONSTANS (CO) is a critical regulator of flowering that combines photoperiodic and circadian signals in Arabidopsis (Arabidopsis thaliana). CO is expressed in multiple tissues, including seedling roots and young leaves. However, the roles and underlying mechanisms of CO in modulating physiological processes outside of flowering remain obscure. Here, we show that the expression of CO responds to salinity treatment. CO negatively mediated salinity tolerance under long-day (LD) conditions. Seedlings from co-mutants were more tolerant to salinity stress, whereas overexpression of CO resulted in plants with reduced tolerance to salinity stress. Further genetic analyses revealed the negative involvement of GIGANTEA (GI) in salinity tolerance requires a functional CO. Mechanistic analysis demonstrated that CO physically interacts with 4 critical basic leucine zipper (bZIP) transcription factors; ABSCISIC ACID-RESPONSIVE ELEMENT BINDING FACTOR1 (ABF1), ABF2, ABF3, and ABF4. Disrupting these ABFs made plants hypersensitive to salinity stress, demonstrating that ABFs enhance salinity tolerance. Moreover, ABF mutations largely rescued the salinity-tolerant phenotype of co-mutants. CO suppresses the expression of several salinity-responsive genes and influences the transcriptional regulation function of ABF3. Collectively, our results show that the LD-induced CO works antagonistically with ABFs to modulate salinity responses, thus revealing how CO negatively regulates plant adaptation to salinity stress.

U-box E3 ubiquitin ligase PUB8 attenuates abscisic acid responses during early seedling growth.

ABSCISIC ACID-INSENSITIVE3 (ABI3) and ABI5 are 2 crucial transcription factors in abscisic acid (ABA) signaling, and their homeostasis at the protein level plays a decisive role in seed germination and subsequent seedling growth. Here, we found that PLANT U-BOX 8 (PUB8), a U-box E3 ubiquitin ligase, physically interacts with ABI3 and ABI5 and negatively regulates ABA responses during early Arabidopsis (Arabidopsis thaliana) seedling growth. Loss-of-function pub8 mutants were hypersensitive to ABA-inhibited cotyledon greening, while lines overexpressing PUB8 with low levels of ABI5 protein abundance were insensitive to ABA. Genetic analyses showed that ABI3 and ABI5 were required for the ABA-sensitive phenotype of pub8, indicating that PUB8 functions upstream of ABI3 and ABI5 to regulate ABA responses. Biochemical analyses showed that PUB8 can associate with ABI3 and ABI5 for degradation through the ubiquitin-mediated 26S proteasome pathway. Correspondingly, loss-of-function of PUB8 led to enhanced ABI3 and ABI5 stability, while overexpression of PUB8 impaired accumulation of ABI3 and ABI5 in planta. Further phenotypic analysis indicated that PUB8 compromised the function of ABI5 during early seedling growth. Taken together, our results reveal the regulatory role of PUB8 in modulating the early seedling growth by controlling the homeostasis of ABI3 and ABI5.

The Arabidopsis circadian clock protein PRR5 interacts with and stimulates ABI5 to modulate abscisic acid signaling during seed germination.

Seed germination and postgerminative growth require the precise coordination of multiple intrinsic and environmental signals. The phytohormone abscisic acid (ABA) suppresses these processes in Arabidopsis thaliana and the circadian clock contributes to the regulation of ABA signaling. However, the molecular mechanism underlying circadian clock-mediated ABA signaling remains largely unknown. Here, we found that the core circadian clock proteins PSEUDO-RESPONSE REGULATOR5 (PRR5) and PRR7 physically associate with ABSCISIC ACID-INSENSITIVE5 (ABI5), a crucial transcription factor of ABA signaling. PRR5 and PRR7 positively modulate ABA signaling redundantly during seed germination. Disrupting PRR5 and PRR7 simultaneously rendered germinating seeds hyposensitive to ABA, whereas the overexpression of PRR5 enhanced ABA signaling to inhibit seed germination. Consistent with this, the expression of several ABA-responsive genes is upregulated by PRR proteins. Genetic analysis demonstrated that PRR5 promotes ABA signaling mainly dependently on ABI5. Further mechanistic investigation revealed that PRR5 stimulates the transcriptional function of ABI5 without affecting its stability. Collectively, our results indicate that these PRR proteins function synergistically with ABI5 to activate ABA responses during seed germination, thus providing a mechanistic understanding of how ABA signaling and the circadian clock are directly integrated through a transcriptional complex involving ABI5 and central circadian clock components.

Jasmonate-regulated root growth inhibition and root hair elongation.

The phytohormone jasmonate is an essential endogenous signal in the regulation of multiple plant processes for environmental adaptation, such as primary root growth inhibition and root hair elongation. Perception of environmental stresses promotes the accumulation of jasmonate, which is sensed by the CORONATINE INSENSITIVE1 (COI1)-JASMONATE ZIM-DOMAIN (JAZ) co-receptor, triggering the degradation of JAZ repressors and induction of transcriptional reprogramming. The basic helix-loop-helix (bHLH) subgroup IIIe transcription factors MYC2, MYC3, and MYC4 are the most extensively characterized JAZ-binding factors and together stimulate jasmonate-signaled primary root growth inhibition. Conversely, the bHLH subgroup IIId transcription factors (i.e. bHLH3 and bHLH17) physically associate with JAZ proteins and suppress jasmonate-induced root growth inhibition. For root hair development, JAZ proteins interact with and inhibit ROOT HAIR DEFECTIVE 6 (RHD6) and RHD6 LIKE1 (RSL1) transcription factors to modulate jasmonate-enhanced root hair elongation. Moreover, jasmonate also interacts with other signaling pathways (such as ethylene and auxin) to regulate primary root growth and/or root hair elongation. Here, we review recent progress into jasmonate-mediated primary root growth and root hair development.

Challenging battles of plants with phloem-feeding insects and prokaryotic pathogens.

For the past 4 decades, intensive molecular studies of mostly leaf mesophyll cell-infecting pathogens and chewing insects have led to compelling models of plant-pathogen and plant-insect interactions. Yet, some of the most devastating pathogens and insect pests live in or feed on the phloem, a systemic tissue belonging to the plant vascular system. Phloem tissues are difficult to study, and phloem-inhabiting pathogens are often impossible to culture, thus limiting our understanding of phloem-insect/pathogen interactions at a molecular level. In this Perspective, we highlight recent literature that reports significant advances in the understanding of phloem interactions with insects and prokaryotic pathogens and attempt to identify critical questions that need attention for future research. It is clear that study of phloem-insect/pathogen interactions represents an exciting frontier of plant science, and influx of new scientific expertise and funding is crucial to achieve faster progress in this important area of research that is integral to global food security.

The role of water in plant-microbe interactions.

Throughout their life plants are associated with various microorganisms, including commensal, symbiotic and pathogenic microorganisms. Pathogens are genetically adapted to aggressively colonize and proliferate in host plants to cause disease. However, disease outbreaks occur only under permissive environmental conditions. The interplay between host, pathogen and environment is famously known as the 'disease triangle'. Among the environmental factors, rainfall events, which often create a period of high atmospheric humidity, have repeatedly been shown to promote disease outbreaks in plants, suggesting that the availability of water is crucial for pathogenesis. During pathogen infection, water-soaking spots are frequently observed on infected leaves as an early symptom of disease. Recent studies have shown that pathogenic bacteria dedicate specialized virulence proteins to create an aqueous habitat inside the leaf apoplast under high humidity. Water availability in the apoplastic environment, and probably other associated changes, can determine the success of potentially pathogenic microbes. These new findings reinforce the notion that the fight over water may be a major battleground between plants and pathogens. In this article, we will discuss the role of water availability in host-microbe interactions, with a focus on plant-bacterial interactions.

Jasmonate Negatively Regulates Stomatal Development in Arabidopsis Cotyledons.

Stomata are ports that facilitate gas and water vapor exchange between plants and their environment. Stomatal development is strictly regulated by endogenous signals and environmental cues. Jasmonate is an important signal that modulates multiple physiological processes in plants, yet the molecular mechanisms underlying its interactions with other developmental signaling pathways remain poorly understood. Here, we show that jasmonate negatively regulates stomatal development in Arabidopsis (Arabidopsis thaliana) cotyledons. Cotyledons of the wild type and stomata-overproliferating mutants (such as too many mouths-1 and stomatal density and distribution1-1) treated with methyl jasmonate exhibit a clear reduction in stomata number. By contrast, blocking endogenous jasmonate biosynthesis or perception enhanced stomatal development. Moreover, three MYC transcription factors involved in jasmonate signaling, MYC2, MYC3, and MYC4, were found to redundantly modulate jasmonate-inhibited stomatal development. A genetic analysis showed that these MYC proteins act upstream of the SPEECHLESS and FAMA transcription factors to mediate stomatal development. Furthermore, jasmonate repression of stomatal development is dependent on these three MYC transcription factors, as stomatal development of the myc2 myc3 myc4 triple mutant was insensitive to methyl jasmonate treatment. Collectively, our study demonstrates that jasmonate and MYC transcription factors negatively regulate stomatal development in Arabidopsis cotyledons.

The WRKY57 Transcription Factor Affects the Expression of Jasmonate ZIM-Domain Genes Transcriptionally to Compromise Botrytis cinerea Resistance.

Although necrotrophic pathogens cause many devastating plant diseases, our understanding of the plant defense response to them is limited. Here, we found that loss of function of WRKY57 enhanced the resistance of Arabidopsis (Arabidopsis thaliana) against Botrytis cinerea infection. Further investigation suggested that the negative regulation of WRKY57 against B cinerea depends on the jasmonic acid (JA) signaling pathway. Chromatin immunoprecipitation experiments revealed that WRKY57 directly binds to the promoters of JASMONATE ZIM-DOMAIN1 (JAZ1) and JAZ5, encoding two important repressors of the JA signaling pathway, and activates their transcription. In vivo and in vitro experiments demonstrated that WRKY57 interacts with nuclear-encoded SIGMA FACTOR BINDING PROTEIN1 (SIB1) and SIB2. Further experiments display that the same domain, the VQ motif, of SIB1 and SIB2 interact with WRKY33 and WRKY57. Moreover, transient transcriptional activity assays confirmed that WRKY57 and WRKY33 competitively regulate JAZ1 and JAZ5, SIB1 and SIB2 further enhance these competitions of WRKY57 to WRKY33. Therefore, coordinated regulation of Arabidopsis against B cinerea by transcription activators and repressors would benefit plants by allowing fine regulation of defense.

Jasmonate regulates leaf senescence and tolerance to cold stress: crosstalk with other phytohormones.

Plants are challenged with numerous abiotic stresses, such as drought, cold, heat, and salt stress. These environmental stresses are major causes of crop failure and reduced yields worldwide. Phytohormones play essential roles in regulating various plant physiological processes and alleviating stressful perturbations. Jasmonate (JA), a group of oxylipin compounds ubiquitous in the plant kingdom, acts as a crucial signal to modulate multiple plant processes. Recent studies have shown evidence supporting the involvement of JA in leaf senescence and tolerance to cold stress. Concentrations of JA are much higher in senescent leaves compared with those in non-senescent ones. Treatment with exogenous JA induces leaf senescence and expression of senescence-associated genes. In response to cold stress, exogenous application of JA enhances Arabidopsis freezing tolerance with or without cold acclimation. Consistently, biosynthesis of endogenous JA is activated in response to cold exposure. JA positively regulates the CBF (C-REPEAT BINDING FACTOR) transcriptional pathway to up-regulate downstream cold-responsive genes and ultimately improve cold tolerance. JA interacts with other hormone signaling pathways (such as auxin, ethylene, and gibberellin) to regulate leaf senescence and tolerance to cold stress. In this review, we summarize recent studies that have provided insights into JA-mediated leaf senescence and cold-stress tolerance.

Arabidopsis WRKY57 functions as a node of convergence for jasmonic acid- and auxin-mediated signaling in jasmonic acid-induced leaf senescence.

Leaf senescence is regulated by diverse developmental and environmental factors. Exogenous jasmonic acid (JA) can induce leaf senescence, whereas auxin suppresses this physiological process. Crosstalk between JA and auxin signaling has been well studied, but not during JA-induced leaf senescence. Here, we found that upon methyl jasmonate treatment, Arabidopsis thaliana wrky57 mutants produced typical leaf senescence symptoms, such as yellowing leaves, low chlorophyll content, and high cell death rates. Further investigation suggested that senescence-associated genes were upregulated in the wrky57 mutants. Chromatin immunoprecipitation experiments revealed that WRKY57 directly binds to the promoters of SENESCENCE4 and SENESCENCE-ASSOCIATED GENE12 and represses their transcription. In vivo and in vitro experiments suggested that WRKY57 interacts with JASMONATE ZIM-DOMAIN4/8 (JAZ4/8) and the AUX/IAA protein IAA29, repressors of the JA and auxin signaling pathways, respectively. Consistent with the opposing functions of JA and auxin in JA-induced leaf senescence, JAZ4/8 and IAA29 also displayed opposite functions in JA-induced leaf senescence and competitively interacted with WRKY57. Our results suggested that the JA-induced leaf senescence process can be antagonized by auxin via WRKY57. Moreover, WRKY57 protein levels were downregulated by JA but upregulated by auxin. Therefore, as a repressor in JA-induced leaf senescence, WRKY57 is a common component of the JA- and auxin-mediated signaling pathways.

Association between the triglyceride glucose index, triglyceride-glucose body mass index and diabetic kidney disease in adults with newly diagnosed type 2 diabetes.

Background: The triglyceride glucose (TyG) index has been proved to be a reliable marker of diabetic kidney disease (DKD). Objective: We further investigated the association between TyG index, and its derivative, triglyceride-glucose body mass index (TyG-BMI), and the risk of DKD among adults with newly diagnosed type 2 diabetes (T2D). Methods: This cross-sectional study was conducted among patients with newly diagnosed T2D. We assessed the correlation between TyG index, TyG-BMI, and the risk of DKD using logistic regression analysis, restricted cubic spline analysis, trend tests, receiver operating characteristic curve, and subgroup analyses. Results: Among the 924 included patients, 199 (21.5%) had DKD. Logistic regression revealed that TyG index (odds ratio [OR] 1.232, 95% confidence interval [CI] 1.064-1.428, p = 0.005) and TyG-BMI (OR 1.003, 95% CI 1.000-1.006, p = 0.021) were risk factors for DKD. The trend test demonstrated a dose-response association between TyG index (p for trend = 0.004), TyG-BMI (p for trend = 0.035), and the risk of DKD. Restricted cubic spline analysis indicated a nonlinear correlation between TyG index and the risk of DKD, with an increase in the risk of DKD when the TyG index was greater than 9.68 (p for nonlinearity = 0.014). In contrast, TyG-BMI and the risk of DKD exhibited a linear dose-response relationship, with an increase in the risk of DKD when the TyG-BMI was greater than 243 (p for nonlinearity = 0.034). According to the receiver operating characteristic curve, the optimal cutoff values for TyG index and TyG-BMI were 10.08 and 221.5, respectively. Conclusion: Among newly diagnosed T2D patients, the risk of DKD increases with the increase of TyG index and TyG-BMI, with their respective cut-off values being 9.68 and 243. Both TyG index and TyG-BMI have poor diagnostic value for the risk of DKD.

Clinical features of early-onset type 2 diabetes and its association with triglyceride glucose-body mass index: a cross-sectional study.

Objective: The incidence of early-onset type 2 diabetes (T2D) has increased significantly, with insulin resistance (IR) and obesity being the main drivers of its onset. This study aims to investigate the clinical characteristics of early-onset T2D and its association with triglyceride glucose body mass index (TyG-BMI), an emerging surrogate of IR. Methods: A total of 1000 adults newly diagnosed with T2D were enrolled and divided into early-onset T2D (18~40 years, N=500) and late-onset T2D groups (≥40 years, N=500). Independent t and chi-squared tests were used to compare the characteristics of the two groups, and logistic regression analysis, trend tests, restricted cubic spline curves (RCSs), and receiver operating characteristic (ROC) curves were used to identify the relationship between TyG-BMI and early-onset T2D. Results: Patients with early-onset T2D were more likely to have a higher body mass index (BMI), hemoglobin A1C (HbA1c), fasting plasma glucose (FPG), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), serum uric acid (SUA), triglyceride glucose index (TyG), and TyG-BMI (P < 0.05). A higher TyG-BMI was associated with an increased risk of early-onset T2D (P < 0.001). The RCSs showed a nonlinear relationship between TyG-BMI and early-onset T2D, and the slope of the curve increased with an increase in TyG-BMI (P for nonlinearity < 0.001). In the subgroup analysis, additive interactions between TyG-BMI and the risk of early-onset T2D were observed for sex, family history of diabetes, BMI, fatty liver, and hypertension (P < 0.001). ROC curve showed that the area under the curve of TyG-BMI was 0.6781, which was larger than its main components (TyG, BMI, FPG, TG). The best cutoff value was 254.865, the sensitivity was 74.6%, and the specificity was 53.6%. Conclusion: Patients with early-onset T2D are characterized by severe IR, metabolic disorders, and being overweight/obese and an increase in TyG-BMI is independently associated with an increased risk of early-onset T2D.

Development and Validation of a Risk Prediction Model for Ketosis-Prone Type 2 Diabetes Mellitus Among Patients Newly Diagnosed with Type 2 Diabetes Mellitus in China.

Background: We established a nomogram for ketosis-prone type 2 diabetes mellitus (KP-T2DM) in the Chinese adult population in order to identify high-risk groups early and intervene in the disease progression in a timely manner. Methods: We reviewed the medical records of 924 adults with newly diagnosed T2DM from January 2018 to June 2021. All patients were randomly divided into the training and validation sets at a ratio of 7:3. The least absolute shrinkage and selection operator regression analysis method was used to screen the predictors of the training set, and the multivariable logistic regression analysis was used to establish the nomogram prediction model. We verified the prediction model using the receiver operating characteristic (ROC) curve, judged the model's goodness-of-fit using the Hosmer-Lemeshow goodness-of-fit test, and predicted the risk of ketosis using the decision curve analysis. Results: A total of 21 variables were analyzed, and four predictors-hemoglobin A1C, 2-hour postprandial blood glucose, 2-hour postprandial C-peptide, and age-were established. The area under the ROC curve for the training and validation sets were 0.8172 and 0.8084, respectively. The Hosmer-Lemeshow test showed that the prediction model and validation set have a high degree of fit. The decision curve analysis curve showed that the nomogram had better clinical applicability when the threshold probability of the patients was 0.03-0.79. Conclusion: The nomogram based on hemoglobin A1C, 2-hour postprandial blood glucose, 2-hour postprandial C-peptide, and age has good performance and can serve as a favorable tool for clinicians to predict KP-T2DM.

Arabidopsis ABRE-binding factors modulate salinity-induced inhibition of root hair growth by interacting with and suppressing RHD6.

Soil salinity causes crop losses worldwide. Root hairs are the primary targets of salt stress, however, the signaling networks involved in the precise regulation of root hair growth and development by salinity are poorly understood. Here, we confirmed that salt stress inhibits the number and length of root hairs in Arabidopsis. We found that the master regulator of root hair development and growth, the RHD6 transcription factor, is involved in this process, as salt treatment largely compromised root hair overaccumulation in RHD6-overexpressing plants. Yeast-two-hybrid and co-immunoprecipitation analyses revealed that RHD6 physically interacts with ABF proteins, the master transcription factors in abscisic acid signaling, which is involved in tolerance to several stresses including salinity. Phenotypic analyses showed that ABF proteins, which function upstream of RHD6, positively modulate the salinity-induced inhibition of root hair development. Further analyses showed that ABF3 suppresses the transcriptional activation activity of RHD6, thereby regulating the expression of genes related to root hair development. Overexpression of ABF3 reduced the root hair-overgrowing phenotype of RHD6-overexpressing plants. Collectively, our results demonstrate an essential signaling module in which ABF proteins directly suppress the transcriptional activation activity of RHD6 to reduce the length and number of root hairs under salt stress conditions.

Stem hydraulic traits and leaf water-stress tolerance are co-ordinated with the leaf phenology of angiosperm trees in an Asian tropical dry karst forest.

BACKGROUND AND AIMS: The co-occurring of evergreen and deciduous angiosperm trees in Asian tropical dry forests on karst substrates suggests the existence of different water-use strategies among species. In this study it is hypothesized that the co-occurring evergreen and deciduous trees differ in stem hydraulic traits and leaf water relationships, and there will be correlated evolution in drought tolerance between leaves and stems. METHODS: A comparison was made of stem hydraulic conductivity, vulnerability curves, wood anatomy, leaf life span, leaf pressure-volume characteristics and photosynthetic capacity of six evergreen and six deciduous tree species co-occurring in a tropical dry karst forest in south-west China. The correlated evolution of leaf and stem traits was examined using both traditional and phylogenetic independent contrasts correlations. KEY RESULTS: It was found that the deciduous trees had higher stem hydraulic efficiency, greater hydraulically weighted vessel diameter (D(h)) and higher mass-based photosynthetic rate (A(m)); while the evergreen species had greater xylem-cavitation resistance, lower leaf turgor-loss point water potential (π(0)) and higher bulk modulus of elasticity. There were evolutionary correlations between leaf life span and stem hydraulic efficiency, A(m), and dry season π(0). Xylem-cavitation resistance was evolutionarily correlated with stem hydraulic efficiency, D(h), as well as dry season π(0). Both wood density and leaf density were closely correlated with leaf water-stress tolerance and A(m). CONCLUSIONS: The results reveal the clear distinctions in stem hydraulic traits and leaf water-stress tolerance between the co-occurring evergreen and deciduous angiosperm trees in an Asian dry karst forest. A novel pattern was demonstrated linking leaf longevity with stem hydraulic efficiency and leaf water-stress tolerance. The results show the correlated evolution in drought tolerance between stems and leaves.

Heat Shock 70 kDa Protein Cognate 3 of Brown Planthopper Is Required for Survival and Suppresses Immune Response in Plants.

The brown planthopper (Nilaparvata lugens) is a monophagous pest of rice (Oryza sativa), which threatens food security around the world. Insect Heat shock proteins 70 kDa (Hsp70s) play a key role in insect growth and development, however, if they also modulate the plant physiological processes is still unclear. In this study, we identified the Heat shock 70 kDa protein cognate 3 (NlHSC70-3) of BPH from compared protein profiles of Nipponbare tissues after BPH infestation via LC/MS. NlHSC70-3 has a predicted signal peptide and displays high transcription levels in the salivary glands, which further supported that it is secreted into plants by BPH during the feeding process. Using RNA interference (RNAi), we showed that NlHSC70-3 is indispensable for the survival of BPH on rice. Most importantly, NlHSC70-3 mediates the plant immune responses including cell death, flg22-induced ROS burst and defense-related gene expression in N. benthamiana. These results demonstrate that NlHSC70-3 may function as an effector manipulating plant physiological processes to facilitate pest survival on rice, which provides a new potential target for future pest control.