Deciphering PDH1's role in mung bean domestication: a genomic perspective on pod dehiscence.

Mung bean (Vigna radiata) stands as a crucial legume crop in Asia, contributing to food security. However, our understanding of the underlying genetic foundation governing domesticated agronomic traits, especially those linked to pod architecture, remains largely unexplored. In this study, we delved into the genomic divergence between wild and domesticated mung bean varieties, leveraging germplasm obtained from diverse sources. Our findings unveiled pronounced variation in promoter regions (35%) between the two mung bean subpopulations, suggesting substantial changes in gene expression patterns during domestication. Leveraging transcriptome analysis using distinct reproductive stage pods and subpopulations, we identified candidate genes responsible for pod and seed architecture development, along with Genome-Wide Association Studies (GWAS) and Quantitative Trait Locus (QTL) analysis. Notably, our research conclusively confirmed PDH1 as a parallel domesticated gene governing pod dehiscence in legumes. This study imparts valuable insights into the genetic underpinnings of domesticated agronomic traits in mung bean, and simultaneously highlighting the parallel domestication of pivotal traits within the realm of legume crops.

SoyDNGP: a web-accessible deep learning framework for genomic prediction in soybean breeding.

Soybean is a globally significant crop, playing a vital role in human nutrition and agriculture. Its complex genetic structure and wide trait variation, however, pose challenges for breeders and researchers aiming to optimize its yield and quality. Addressing this biological complexity requires innovative and accurate tools for trait prediction. In response to this challenge, we have developed SoyDNGP, a deep learning-based model that offers significant advancements in the field of soybean trait prediction. Compared to existing methods, such as DeepGS and DNNGP, SoyDNGP boasts a distinct advantage due to its minimal increase in parameter volume and superior predictive accuracy. Through rigorous performance comparison, including prediction accuracy and model complexity, SoyDNGP represents improved performance to its counterparts. Furthermore, it effectively predicted complex traits with remarkable precision, demonstrating robust performance across different sample sizes and trait complexities. We also tested the versatility of SoyDNGP across multiple crop species, including cotton, maize, rice and tomato. Our results showed its consistent and comparable performance, emphasizing SoyDNGP's potential as a versatile tool for genomic prediction across a broad range of crops. To enhance its accessibility to users without extensive programming experience, we designed a user-friendly web server, available at http://xtlab.hzau.edu.cn/SoyDNGP. The server provides two features: 'Trait Lookup', offering users the ability to access pre-existing trait predictions for over 500 soybean accessions, and 'Trait Prediction', allowing for the upload of VCF files for trait estimation. By providing a high-performing, accessible tool for trait prediction, SoyDNGP opens up new possibilities in the quest for optimized soybean breeding.

The effectiveness of COVID-19 testing and contact tracing in a US city.

Although testing, contact tracing, and case isolation programs can mitigate COVID-19 transmission and allow the relaxation of social distancing measures, few countries worldwide have succeeded in scaling such efforts to levels that suppress spread. The efficacy of test-trace-isolate likely depends on the speed and extent of follow-up and the prevalence of SARS-CoV-2 in the community. Here, we use a granular model of COVID-19 transmission to estimate the public health impacts of test-trace-isolate programs across a range of programmatic and epidemiological scenarios, based on testing and contact tracing data collected on a university campus and surrounding community in Austin, TX, between October 1, 2020, and January 1, 2021. The median time between specimen collection from a symptomatic case and quarantine of a traced contact was 2 days (interquartile range [IQR]: 2 to 3) on campus and 5 days (IQR: 3 to 8) in the community. Assuming a reproduction number of 1.2, we found that detection of 40% of all symptomatic cases followed by isolation is expected to avert 39% (IQR: 30% to 45%) of COVID-19 cases. Contact tracing is expected to increase the cases averted to 53% (IQR: 42% to 58%) or 40% (32% to 47%), assuming the 2- and 5-day delays estimated on campus and in the community, respectively. In a tracing-accelerated scenario, in which 75% of contacts are notified the day after specimen collection, cases averted increase to 68% (IQR: 55% to 72%). An accelerated contact tracing program leveraging rapid testing and electronic reporting of test results can significantly curtail local COVID-19 transmission.

Real-time pandemic surveillance using hospital admissions and mobility data.

Forecasting the burden of COVID-19 has been impeded by limitations in data, with case reporting biased by testing practices, death counts lagging far behind infections, and hospital census reflecting time-varying patient access, admission criteria, and demographics. Here, we show that hospital admissions coupled with mobility data can reliably predict severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission rates and healthcare demand. Using a forecasting model that has guided mitigation policies in Austin, TX, we estimate that the local reproduction number had an initial 7-d average of 5.8 (95% credible interval [CrI]: 3.6 to 7.9) and reached a low of 0.65 (95% CrI: 0.52 to 0.77) after the summer 2020 surge. Estimated case detection rates ranged from 17.2% (95% CrI: 11.8 to 22.1%) at the outset to a high of 70% (95% CrI: 64 to 80%) in January 2021, and infection prevalence remained above 0.1% between April 2020 and March 1, 2021, peaking at 0.8% (0.7-0.9%) in early January 2021. As precautionary behaviors increased safety in public spaces, the relationship between mobility and transmission weakened. We estimate that mobility-associated transmission was 62% (95% CrI: 52 to 68%) lower in February 2021 compared to March 2020. In a retrospective comparison, the 95% CrIs of our 1, 2, and 3 wk ahead forecasts contained 93.6%, 89.9%, and 87.7% of reported data, respectively. Developed by a task force including scientists, public health officials, policy makers, and hospital executives, this model can reliably project COVID-19 healthcare needs in US cities.

Duplicated antagonistic EPF peptides optimize grass stomatal initiation.

Peptide signaling has emerged as a key component of plant growth and development, including stomatal patterning, which is crucial for plant productivity and survival. Although exciting progress has been made in understanding EPIDERMAL PATTERNING FACTOR (EPF) signaling in Arabidopsis, the mechanisms by which EPF peptides control different stomatal patterns and morphologies in grasses are poorly understood. Here, by examining expression patterns, overexpression transgenics and cross-species complementation, the antagonistic stomatal ligands orthologous to Arabidopsis AtEPF2 and AtSTOMAGEN/AtEPFL9 peptides were identified in Triticum aestivum (wheat) and the grass model organism Brachypodium distachyon. Application of bioactive BdEPF2 peptides inhibited stomatal initiation, but not the progression or differentiation of stomatal precursors in Brachypodium. Additionally, the inhibitory roles of these EPF peptides during grass stomatal development were suppressed by the contrasting positive action of the BdSTOMAGEN peptide in a dose-dependent manner. These results not only demonstrate how conserved EPF peptides that control different stomatal patterns exist in nature, but also suggest new strategies to improve crop yield through the use of plant-derived antagonistic peptides that optimize stomatal density on the plant epidermis.

Deterministic All-Optical Quantum Teleportation of Four Degrees of Freedom.

Quantum teleportation, disembodied transfer of the unknown quantum state between two locations, has been experimentally demonstrated for both discrete and continuous variable states in one degree of freedom (DOF). Generally, multiple DOFs are needed to fully characterize a quantum state. Therefore, to implement intact quantum teleportation, multiple DOFs of quantum state should be teleported simultaneously. Recently, teleporting a single photon encoded in two DOFs has been experimentally demonstrated in discrete variable regime. However, the teleportation of more than two DOFs remains unexplored. Here, by utilizing continuous variable hyperentanglement in four DOFs (azimuthal and radial indexes of Laguerre-Gaussian mode, frequency, and polarization), we experimentally demonstrate deterministic all-optical quantum teleportation of four DOFs. Moreover, we experimentally construct 24 parallel teleportation channels. Our results pave the way for deterministically implementing multiple-DOF quantum communication protocols.

Cloning and Characterization of Chitin Deacetylase from Euphausia superba.

Chitin deacetylase (CDA) can catalyze the deacetylation of chitin to produce chitosan. In this study, we identified and characterized a chitin deacetylase gene from Euphausia superba (EsCDA-9k), and a soluble recombinant protein chitin deacetylase from Euphausia superba of molecular weight 45 kDa was cloned, expressed, and purified. The full-length cDNA sequence of EsCDA-9k was 1068 bp long and encoded 355 amino acid residues that contained the typical domain structure of carbohydrate esterase family 4. The predicted three-dimensional structure of EsCDA-9k showed a 67.32% homology with Penaeus monodon. Recombinant chitin deacetylase had the highest activity at 40 °C and pH 8.0 in Tris-HCl buffer. The enzyme activity was enhanced by metal ions Co2+, Fe3+, Ca2+, and Na+, while it was inhibited by Zn2+, Ba2+, Mg2+, and EDTA. Molecular simulation of EsCDA-9k was conducted based on sequence alignment and homology modeling. The EsCDA-9k F18G mutant showed a 1.6-fold higher activity than the wild-type enzyme. In summary, this is the first report of the cloning and heterologous expression of the chitin deacetylase gene in Euphausia superba. The characterization and function study of EsCDA-9k will serve as an important reference point for future application.

Self-healing of Einstein-Rosen-Podolsky steering after an obstruction.

Einstein-Rosen-Podolsky (EPR) steering describes the "spooky action at a distance" that one party can instantaneously affect the states of another distant party if they share quantum correlations. Due to its intriguing properties, EPR steering is recognized as an essential resource for a number of quantum information tasks. However, EPR steering may be destroyed when distributed in practical environments. Here, we experimentally show that EPR steering can self-heal after being destroyed by an obstruction. Such self-healing of EPR steering originates from the self-healing property of Bessel-Gaussian beams which are utilized to distribute EPR steering. For comparison, we show that when distributed using fundamental Gaussian beams, EPR steering cannot self-heal after an obstruction under similar conditions. Our results shed new light on constructing EPR-steering-based quantum information tasks in practical environments and provide a promising platform to study EPR steering.

Enhancing and flattening multiplexed quantum entanglement by utilizing perfect vortex modes.

We experimentally demonstrate a method for enhancing and flattening multiplexed entanglement in the four-wave mixing (FWM) process, which is implemented by replacing Laguerre-Gaussian (LG) modes with perfect vortex (PV) modes. For the topological charge l ranging from -5 to 5, the entanglement degrees of orbital angular momentum (OAM) multiplexed entanglement with PV modes are all larger than those of OAM multiplexed entanglement with LG modes. More importantly, for OAM multiplexed entanglement with PV modes, the degree of entanglement almost does not change with the topology value. In other words, we experimentally flatten the OAM multiplexed entanglement, which cannot be achieved in OAM multiplexed entanglement with LG modes based on the FWM process. In addition, we experimentally measure the entanglement with coherent superposition OAM modes. Our scheme provides a new, to the best of our knowledge, platform to construct an OAM multiplexed system and may find potential applications in realizing the parallel quantum information protocols.

Ultra-Large-Scale Deterministic Entanglement Containing 2×20 400 Optical Modes Based on Time-Delayed Quantum Interferometer.

Quantum entanglement is an indispensable resource for implementing quantum information processing. The scale of quantum entanglement directly determines its quantum information processing capability. Therefore, it is of great importance to generate ultra-large-scale (ULS) quantum entanglement for the development of quantum information science and technology. Many efforts have been made to increase the scale of quantum entanglement. Recently, time-domain multiplexing has been introduced into continuous-variable (CV) quantum systems to greatly enlarge the scale of quantum entanglement. In this Letter, based on a time-delayed quantum interferometer, we theoretically propose and experimentally demonstrate a scheme for generating an ULS CV deterministic entanglement containing 2×20 400 optical modes. In addition, such ULS entanglement contains 81 596 squeezed modes. Our results provide a new platform for implementing ULS CV quantum information processing.

Environmental, economic, and energy analysis of municipal solid waste incineration under anoxic environment in Tibet Plateau.

The first Municipal solid waste incineration (MSWI) plant in Lhasa, Tibet, the plateau region of China, started its operation in 2018. Considering the elevation and extreme climate (low pressure and low oxygen content) in Tibet, noticeable differences may be envisaged compared to MSWI elsewhere. The aim of this study is to evaluate the environmental impacts, economic benefits, and energy efficiency of this MSWI project with three representative MSWI case in plain region using Life cycle assessment (LCA), Cost-benefit analysis (CBA), and energy analysis methods. The result showed that enhancing blast volume and cross-sectional area of the boiler help adapt to the oxygen-deficient environment. GaBi model was employed based on the CML 2001 methodology to perform LCA. LCA shows that the Lhasa MSWI project has lower positive environment impacts than the projects in plain region. More attention is needed for the deficiencies in flue gas emissions of MSWI in the plateau region. CBA shows that the payback period is 11.97 years and the internal rate of return is 8.75%. The energy analysis indicates that the boiler energy efficiency is up to 81.92%. MSWI subject to minor changes seems suitable to Tibetan plateau, and can be deployed further.

CRISPR/Cas9 Gene Editing of NtAITRs, a Family of Transcription Repressor Genes, Leads to Enhanced Drought Tolerance in Tobacco.

Tobacco is a cash crop throughout the world, and its growth and development are affected by abiotic stresses including drought stress; therefore, drought-tolerant breeding may help to improve tobacco yield and quality under drought stress conditions. Considering that the plant hormone ABA (abscisic acid) is able to regulate plant responses to abiotic stresses via activating ABA response genes, the characterization of ABA response genes may enable the identification of genes that can be used for molecular breeding to improve drought tolerance in tobacco. We report here the identification of NtAITRs (Nicotiana tabacum ABA-induced transcription repressors) as a family of novel regulators of drought tolerance in tobacco. Bioinformatics analysis shows that there are a total of eight NtAITR genes in tobacco, and all the NtAITRs have a partially conserved LxLxL motif at their C-terminus. RT-PCR results show that the expression levels of at least some NtAITRs were increased in response to ABA and drought treatments, and NtAITRs, when recruited to the Gal4 promoter via a fused GD (Gal4 DNA-binding domain), were able to repress transcription activator LD-VP activated expression of the LexA-Gal4-GUS reporter gene. Roles of NtAITRs in regulating drought tolerance in tobacco were analyzed by generating CRISPR/Cas9 gene-edited mutants. A total of three Cas9-free ntaitr12356 quintuple mutants were obtained, and drought treatment assays show that drought tolerance was increased in the ntaitr12356 quintuple mutants. On the other hand, results of seed germination and seedling greening assays show that ABA sensitivity was increased in the ntaitr12356 quintuple mutants, and the expression levels of some ABA signaling key regulator genes were altered in the ntaitr12356-c3 mutant. Taken together, our results suggest that NtAITRs are ABA-responsive genes, and that NtAITRs function as transcription repressors and negatively regulate drought tolerance in tobacco, possibly by affecting plant ABA response via affecting the expression of ABA signaling key regulator genes.

AtEAU1 and AtEAU2, Two EAR Motif-Containing ABA Up-Regulated Novel Transcription Repressors Regulate ABA Response in Arabidopsis.

EAR (Ethylene-responsive element binding factor-associated Amphiphilic Repression) motif-containing transcription repressors have been shown to regulate plant growth and development, and plant responses to plant hormones and environmental stresses including biotic and abiotic stresses. However, the functions of most EAR-motif-containing proteins remain largely uncharacterized. The plant hormone abscisic acid (ABA) also plays important roles in regulating plant responses to abiotic stresses via activation/repression of ABA-responsive genes. We report here the identification and functional characterization of two ABA-responsive EAR motif-containing protein genes, AtEAU1 (Arabidopsis thaliana EAR motif-containing ABAUp-regulated 1) and AtEAU2. Quantitative RT-PCR results show that the expressions of AtEAU1 and AtEAU2 were increased by ABA treatment, and were decreased in the ABA biosynthesis mutant aba1-5. Assays in transfected Arabidopsis protoplasts show that both AtEAU1 and AtEAU2 were specifically localized in the nucleus, and when recruited to the promoter region of the reporter gene by a fused DNA binding domain, repressed reporter gene expression. By using T-DNA insertion mutants and a gene-edited transgene-free mutant generated by CRISPR/Cas9 gene editing, we performed ABA sensitivity assays, and found that ABA sensitivity in the both ateau1 and ateau2 single mutants was increased in seedling greening assays. ABA sensitivity in the ateau1 ateau2 double mutants was also increased, but was largely similar to the ateau1 single mutants. On the other hand, all the mutants showed a wild type response to ABA in root elongation assays. Quantitative RT-PCR results show that the expression level of PYL4, an ABA receptor gene was increased, whereas that of ABI2, a PP2C gene was decreased in the ateau1 and ateau1 single, and the ateau1 ateau2 double mutants. In summary, our results suggest that AtEAU1 and AtEAU2 are ABA-response genes, and AtEAU1 and AtEAU2 are novel EAR motif-containing transcription repressors that negatively regulate ABA responses in Arabidopsis, likely by regulating the expression of some ABA signaling key regulator genes.

Effects of COVID-19 Vaccination Timing and Risk Prioritization on Mortality Rates, United States.

During rollout of coronavirus disease vaccination, policymakers have faced critical trade-offs. Using a mathematical model of transmission, we found that timing of vaccination rollout would be expected to have a substantially greater effect on mortality rate than risk-based prioritization and uptake and that prioritizing first doses over second doses may be lifesaving.

Conserved and non-conserved functions of the rice homologs of the Arabidopsis trichome initiation-regulating MBW complex proteins.

BACKGROUND: Trichome initiation in Arabidopsis is regulated by a MYB-bHLH-WD40 (MBW) transcriptional activator complex formed by the R2R3 MYB transcription factor GLABRA1 (GL1), MYB23 or MYB82, the bHLH transcription factor GLABRA3 (GL3), ENHANCER OF GLABRA3 (EGL3) or TRANSPARENT TESTA8 (TT8), and the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1). However, the functions of the rice homologs of the MBW complex proteins remained uncharacterized. RESULTS: Based on amino acid sequence identity and similarity, and protein interaction prediction, we identified OsGL1s, OsGL3s and OsTTG1s as rice homologs of the MBW complex proteins. By using protoplast transfection, we show that OsGL1D, OsGL1E, OsGL3B and OsTTG1A were predominantly localized in the nucleus, OsGL3B functions as a transcriptional activator and is able to interact with GL1 and TTG1. By using yeast two-hybrid and protoplast transfection assays, we show that OsGL3B is able to interact with OsGL1E and OsTTG1A, and OsGL1E and OsTTG1A are also able to interact with GL3. On the other hand, we found that OsGL1D functions as a transcription activator, and it can interact with GL3 but not OsGL3B. Furthermore, our results show that expression of OsTTG1A in the ttg1 mutant restored the phenotypes including alternations in trichome and root hair formation, seed color, mucilage production and anthocyanin biosynthesis, indicating that OsTTG1A and TTG1 may have similar functions. CONCLUSION: These results suggest that the rice homologs of the Arabidopsis MBW complex proteins are able to form MBW complexes, but may have conserved and non-conserved functions.

A transposon-mediated reciprocal translocation promotes environmental adaptation but compromises domesticability of wild soybeans.

Large structural variations frequently occur in higher plants; however, the impact of such variations on plant diversification, adaptation and domestication remains elusive. Here, we mapped and characterised a reciprocal chromosomal translocation in soybeans and assessed its effects on diversification and adaptation of wild (Glycine soja) and semiwild (Glycine gracilis) soybeans, and domestication of cultivated soybean (Glycine max), by tracing the distribution of the translocation in the USDA Soybean Germplasm Collection and population genetics analysis. We demonstrate that the translocation occurred through CACTA transposon-mediated chromosomal breakage in wild soybean c. 0.34 Ma and is responsible for semisterility in translocation heterozygotes and reduces their reproductive fitness. The translocation has differentiated Continental (i.e. China and Russia) populations from Maritime (i.e. Korea and Japan) populations of G. soja and predominately adapted to cold and dry climates. Further analysis revealed that the divergence of G. max from G. soja predates the translocation event and that G. gracilis is an evolutionary intermediate between G. soja and G. max. Our results highlight the effects of a chromosome rearrangement on the processes leading to plant divergence and adaptation, and provides evidence that suggests G. gracilis, rather than G. soja, as the ancestor of cultivated soybean.

Overlapping obesity-related glomerulopathy and immunoglobulin A nephropathy: clinical and pathologic characteristics and prognosis.

BACKGROUND: In this study, we investigated the clinical and pathologic characteristics and prognosis of overlapping obesity-related glomerulopathy (ORG) and immunoglobulin A nephropathy (IgAN) (ORG + IgAN), which is rare in the clinic. METHODS: We included 62 cases of ORG + IgAN, 110 cases of ORG without other glomerulopathy (ORG alone) and 124 cases of IgAN without other glomerulopathy (IgAN alone). The clinical, pathologic and prognostic data were collected and compared. RESULTS: ORG + IgAN patients showed a higher incidence of body mass index (BMI), higher incidence of hyperuricemia, higher incidence of hypertriglyceridemia and higher blood glucose than the IgAN alone(all P < 0.05). ORG + IgAN patients presented with higher incidence of microscopic hematuria, greater mesangial cell proliferation and a higher proportion of crescents than the ORG alone (all P < 0.05). The ORG + IgAN patients who received corticosteroid or immunosuppressive therapy achieved a higher cumulative rate of partial or complete remission (PR or CR, P = 0.009). However, there was no significant difference in the cumulative renal survival rate between the ORG + IgAN patients in the glucocorticoids/immunosuppressors and non-glucocorticoids/immunosuppressors groups (P = 0.356). Obesity-related focal segmental glomerulosclerosis (O-FSGS) and body mass index (BMI) were significantly associated with poor prognosis (all P < 0.05). CONCLUSIONS: ORG + IgAN should be considered in obese patients who present with metabolic abnormalities and microscopic hematuria. Although corticosteroid or immunosuppressive therapy achieves higher cumulative incidence rates of PR or CR, there is no benefit to long-term prognosis but an increased risk of infection. Moreover, O-FSGS and BMI are significantly associated with poor prognosis.

Normotensive and hypertensive Immunoglobulin a nephropathy with ischemic renal injury: clinicopathological characteristics and prognosis.

OBJECTIVES: This study aimed to investigate the clinicopathological characteristics and prognosis of normotensive and hypertensive IgAN patients with ischemic renal injury. METHODS: A total of 344 cases of IgAN with ischemic renal injury were included in the study, including 99 normotensive IgAN patients (28.8%) and 245 hypertensive IgAN patients (71.2%). In addition, 467 IgAN patients without ischemic renal injury were included as controls, including 205 normotensive patients and 262 hypertensive patients. Clinicopathological and prognostic data were collected and analyzed. RESULTS: Compared with patients without ischemic renal injury, IgAN patients with ischemic renal injury displayed a higher proportion of hypertention, a higher proportion of ischemic glomerulosclerosis, tubular atrophy/interstitial fibrosis and vascular lesions (all p < .05). There was no significant difference in cumulative survival between the normotensive IgAN patients groups (Log-rank χ2 = 0.479; p = .489). Furthermore, ischemic renal injury was not a risk factor for end-point events in normotensive IgAN patients (HR = 1.103; 95% CI: 0.279-4.365; p = .889). There was lower cumulative survival in hypertensive IgAN patients with ischemic renal injury (Log-rank χ2 = 11.352, p = .001). Moreover, ischemic renal injury was a risk factor for end-point events in hypertensive IgAN patients (HR = 1.889; 95% CI: 1.124-3.178; p = .016). CONCLUSIONS: Ischemic renal injury can occur in normotensive IgAN patients. Although the pathological changes may not affect the long-term prognosis of normotensive IgAN patients, the prognosis for hypertensive IgAN patients remains poor. Therefore, increased attention should be paid to the clinical management of ischemic lesions in hypertensive IgAN patients.

The Carboxyl-Terminus of TRANSPARENT TESTA GLABRA1 Is Critical for Its Functions in Arabidopsis.

The Arabidopsis WD40 repeat protein TRANSPARENT TESTA GLABRA1 (TTG1) regulates cell fate determination, including trichome initiation and root hair formation, as well as secondary metabolism such as flavonoid biosynthesis and seed coat mucilage production. TTG1 regulates different processes via regulating the expression of its downstream target genes by forming MYB-bHLH-WD40 (MBW) activator complexes with different R2R3 MYB and bHLH transcription factors. Here, we report the identification of the carboxyl (C)-terminus as a critical domain for TTG1's functions in Arabidopsis. We found that the ttg1Δ15aa mutant shows pleiotropic phenotypes identical to a TTG1 loss-of-function mutant. Gene sequencing indicates that a single nucleotide substitution in TTG1 led to a premature stop at the W327 residue, leading to the production of a truncated TTG1 protein with a deletion of the last 15 C-terminal amino acids. The expression of TTG1 under the control of its native promoter fully restored the ttg1Δ15aa mutant phenotypes. Consistent with these observations, the expression levels of TTG1 downstream genes such as GLABRA2 (GL2) and CAPRICE (CPC) were reduced in the ttg1Δ15aa mutant. Assays in Arabidopsis protoplast show that TTG1Δ15aa failed to interact with the bHLH transcription factor GL3, and the deletion of the last 3 C-terminal amino acids or the 339L amino acid alone fully abolished the interaction of TTG1 with GL3. Furthermore, the expression of TTG1Δ3aa under the control of TTG1 native promoter failed to restore the ttg1Δ15aa mutant phenotypes. Taken together, our results suggest that the C-terminal domain of TTG1 is required for its proper function in Arabidopsis.

Involvement of ABA Responsive SVB Genes in the Regulation of Trichome Formation in Arabidopsis.

Trichome formation in Arabidopsis is regulated by several key regulators, and plants hormones such as gibberellin, salicylic acid, jasmonic acid and cytokinins have been shown to regulate trichome formation by affecting the transcription or activities of the key regulators. We report here the identification of two abscisic acid (ABA) responsive genes, SMALLER TRICHOMES WITH VARIABLE BRANCHES (SVB) and SVB2 as trichome formation regulator genes in Arabidopsis. The expression levels of SVB and SVB2 were increased in response to ABA treatment, their expression levels were reduced in the ABA biosynthesis mutant aba1-5, and they have similar expression pattern. In addition to the trichome defects reported previously for the svb single mutant, we found that even though the trichome numbers were largely unaffected in both the svb and svb2 single mutants generate by using CRISPR/Cas9 gene editing, the trichome numbers were greatly reduced in the svb svb2 double mutants. On the other hand, trichome numbers were increased in SVB or SVB2 overexpression plants. RT-PCR results show that the expression of the trichome formation key regulator gene ENHANCER OF GLABRA3 (EGL3) was affected in the svb svb2 double mutants. Our results suggest that SVB and SVB2 are ABA responsive genes, and SVB and SVB2 function redundantly to regulate trichome formation in Arabidopsis.