WGCNA and transcriptome profiling reveal hub genes for key development stage seed size/oil content between wild and cultivated soybean.

BACKGROUND: Soybean is one of the most important oil crops in the world. The domestication of wild soybean has resulted in significant changes in the seed oil content and seed size of cultivated soybeans. To better understand the molecular mechanisms of seed formation and oil content accumulation, WDD01514 (E1), ZYD00463 (E2), and two extreme progenies (E23 and E171) derived from RILs were used for weighted gene coexpression network analysis (WGCNA) combined with transcriptome analysis. RESULTS: In this study, both seed weight and oil content in E1 and E171 were significantly higher than those in E2 and E23, and 20 DAF and 30 DAF may be key stages of soybean seed oil content accumulation and weight increase. Pathways such as "Photosynthesis", "Carbon metabolism", and "Fatty acid metabolism", were involved in oil content accumulation and grain formation between wild and cultivated soybeans at 20 and 30 DAF according to RNA-seq analysis. A total of 121 oil content accumulation and 189 seed formation candidate genes were screened from differentially expressed genes. WGCNA identified six modules related to seed oil content and seed weight, and 76 candidate genes were screened from modules and network. Among them, 16 genes were used for qRT-PCR and tissue specific expression pattern analysis, and their expression-levels in 33-wild and 23-cultivated soybean varieties were subjected to correlation analysis; some key genes were verified as likely to be involved in oil content accumulation and grain formation. CONCLUSIONS: Overall, these results contribute to an understanding of seed lipid metabolism and seed size during seed development, and identify potential functional genes for improving soybean yield and seed oil quantity.

GmEIL4 enhances soybean (Glycine max) phosphorus efficiency by improving root system development.

Phosphorus (P) deficiency seriously affects plant growth and development and ultimately limits the quality and yield of crops. Here, a new P efficiency-related major quantitative trait locus gene, GmEIL4 (encoding an ethylene-insensitive 3-like 1 protein), was cloned at qP2, which was identified by linkage analysis and genome-wide association study across four environments. Overexpressing GmEIL4 significantly improved the P uptake efficiency by increasing the number, length and surface area of lateral roots of hairy roots in transgenic soybeans, while interfering with GmEIL4 resulted in poor root phenotypic characteristics compared with the control plants under low P conditions. Interestingly, we found that GmEIL4 interacted with EIN3-binding F box protein 1 (GmEBF1), which may regulate the root response to low P stress. We conclude that the expression of GmEIL4 was induced by low-P stress and that overexpressing GmEIL4 improved P accumulation by regulating root elongation and architecture. Analysis of allele variation of GmEIL4 in 894 soybean accessions suggested that GmEIL4 is undergoing artificial selection during soybean evolution, which will benefit soybean production. Together, this study further elucidates how plants respond to low P stress by modifying root structure and provides insight into the great potential of GmEIL4 in crop P-efficient breeding.

HY5-HDA9 orchestrates the transcription of HsfA2 to modulate salt stress response in Arabidopsis.

Integration of light signaling and diverse abiotic stress responses contribute to plant survival in a changing environment. Some reports have indicated that light signals contribute a plant's ability to deal with heat, cold, and stress. However, the molecular link between light signaling and the salt-response pathways remains unclear. We demonstrate here that increasing light intensity elevates the salt stress tolerance of plants. Depletion of HY5, a key component of light signaling, causes Arabidopsis thaliana to become salinity sensitive. Interestingly, the small heat shock protein (sHsp) family genes are upregulated in hy5-215 mutant plants, and HsfA2 is commonly involved in the regulation of these sHsps. We found that HY5 directly binds to the G-box motifs in the HsfA2 promoter, with the cooperation of HISTONE DEACETYLASE 9 (HDA9), to repress its expression. Furthermore, the accumulation of HDA9 and the interaction between HY5 and HDA9 are significantly enhanced by salt stress. On the contrary, high temperature triggers HY5 and HDA9 degradation, which leads to dissociation of HY5-HDA9 from the HsfA2 promoter, thereby reducing salt tolerance. Under salt and heat stress conditions, fine tuning of protein accumulation and an interaction between HY5 and HDA9 regulate HsfA2 expression. This implies that HY5, HDA9, and HsfA2 play important roles in the integration of light signaling with salt stress and heat shock response.

Genome-wide identification of low phosphorus responsive microRNAs in two soybean genotypes by high-throughput sequencing.

MicroRNAs (miRNAs) have been reported to be correlated with various stress responses in soybean, but only a few miRNAs have been demonstrated to respond to low phosphorus (LP) stress. To unravel the response mechanisms of miRNAs to low-P stress, the roots of two representative soybean genotypes with different P efficiency, Nannong94-156 (a LP-tolerant genotype) and Bogao (a LP-sensitive genotype), were used for the construction of RNA sequencing (RNA-seq) libraries under low/normal-P treatment by high-throughput sequencing. In total, 603 existing miRNAs and 1699 novel miRNAs belonging to 248 and 1582 families in all samples were identified, respectively. Among these miRNAs, 777 miRNAs were differentially expressed (DE) across different P levels and genotypes. Furthermore, putative targets of DE miRNAs were predicted, and these miRNAs mainly targeted ERF (ethylene responsive factor), auxin response factors (ARF), zinc finger protein, MYB, and NAC domain transcription factors. Gene ontology (GO) analysis showed that targets of DE miRNAs were significantly enriched in binding, metabolic processes, biological regulation, response to stress, and phosphorus metabolic processes. In addition, the expression profiles of chosen P-responsive miRNAs and target genes were validated by quantitative real-time PCR (qRT-PCR). Our study focused on genome-wide miRNA identification in two representative soybean genotypes under low-P stress. Overall, the DE miRNAs across different P levels and genotypes and their putative target genes will provide useful information for further study of miRNAs mediating low-P response and facilitate improvements in soybean breeding.

Quantitative trait loci analysis of seed oil content and composition of wild and cultivated soybean.

BACKGROUND: Soybean oil is a major source of edible oil, and the domestication of wild soybean has resulted in significant changes in oil content and composition. Extensive efforts have been made to identify genetic loci that are related to soybean oil traits. The objective of this study was to identify quantitative trait loci (QTLs) related to soybean seed oil and compare the fatty acid composition between wild and cultivated soybean. RESULTS: Using the specific-locus amplified fragment sequencing (SLAF-seq) method, a total of 181 recombinant inbred lines (RILs) derived from a cross between wild soybean ZYD00463 (Glycine soja) and cultivated soybean WDD01514 (Glycine max) were genotyped. Finally, a high-density genetic linkage map comprising 11,398 single-nucleotide polymorphism (SNP) markers on 20 linkage groups (LGs) was constructed. Twenty-four stable QTLs for seed oil content and composition were identified by model-based composite interval mapping (CIM) across multiple environments. Among these QTLs, 23 overlapped with or were adjacent to previously reported QTLs. One QTL, qPA10_1 (5.94-9.98 Mb) on Chr. Ten is a novel locus for palmitic acid. In the intervals of stable QTLs, some interesting genes involved in lipid metabolism were detected. CONCLUSIONS: We developed 181 RILs from a cross between wild soybean ZYD00463 and cultivated soybean WDD01514 and constructed a high-density genetic map using the SLAF-seq method. We identified 24 stable QTLs for seed oil content and compositions, which includes qPA10_1 on Chr. 10, a novel locus for palmitic acid. Some interesting genes in the QTL regions were also detected. Our study will provide useful information for scientists to learn about genetic variations in lipid metabolism between wild and cultivated soybean.

Identification of loci controlling adaptation in Chinese soya bean landraces via a combination of conventional and bioclimatic GWAS.

Landraces often contain genetic diversity that has been lost in modern cultivars, including alleles that confer enhanced local adaptation. To comprehensively identify loci associated with adaptive traits in soya bean landraces, for example flowering time, a population of 1938 diverse landraces and 97 accessions of the wild progenitor of cultivated soya bean, Glycine soja was genotyped using tGBS® . Based on 99 085 high-quality SNPs, landraces were classified into three sub-populations which exhibit geographical genetic differentiation. Clustering was inferred from STRUCTURE, principal component analyses and neighbour-joining tree analyses. Using phenotypic data collected at two locations separated by 10 degrees of latitude, 17 trait-associated SNPs (TASs) for flowering time were identified, including a stable locus Chr12:5914898 and previously undetected candidate QTL/genes for flowering time in the vicinity of the previously cloned flowering genes, E1 and E2. Using passport data associated with the collection sites of the landraces, 27 SNPs associated with adaptation to three bioclimatic variables (temperature, daylength, and precipitation) were identified. A series of candidate flowering genes were detected within linkage disequilibrium (LD) blocks surrounding 12 bioclimatic TASs. Nine of these TASs exhibit significant differences in flowering time between alleles within one or more of the three individual sub-populations. Signals of selection during domestication and/or subsequent landrace diversification and adaptation were detected at 38 of the 44 flowering and bioclimatic TASs. Hence, this study lays the groundwork to begin breeding for novel environments predicted to arise following global climate change.

Tissue-Specific Ubiquitination by IPA1 INTERACTING PROTEIN1 Modulates IPA1 Protein Levels to Regulate Plant Architecture in Rice.

Plant architecture, a collection of genetically controlled agronomic traits, is one of the decisive factors that determine grain production. IDEAL PLANT ARCHITECTURE1 (IPA1) encodes a key transcription factor with pleiotropic effects on regulating plant architecture in rice (Oryza sativa), and IPA1 expression is controlled at the posttranscriptional level by microRNA156 and microRNA529. Here, we report the identification and characterization of IPA1 INTERACTING PROTEIN1 (IPI1), a RING-finger E3 ligase that can interact with IPA1 in the nucleus. IPI1 promotes the degradation of IPA1 in panicles, while it stabilizes IPA1 in shoot apexes. Consistent with these findings, the ipi1 loss-of-function mutants showed markedly altered plant architecture, including more tillers, enlarged panicles, and increased yield per plant. Moreover, IPI1 could ubiquitinate the IPA1-mediated complex with different polyubiquitin chains, adding K48-linked polyubiquitin chains in panicles and K63-linked polyubiquitin chains in the shoot apex. These results demonstrate that IPI1 affects plant architecture through precisely tuning IPA1 protein levels in different tissues in rice and provide new insight into the tissue-specific regulation of plant architecture and important genetic resources for molecular breeding.

Pathotype, Resistance Classification, and Seed-Coating Control of Heterodera avenae and H. filipjevi in the North China Plain.

Heterodera avenae and H. filipjevi are cereal cyst nematodes (CCNs) that infect cereals in 16 provinces of China. CCN populations from Xuchang, Tangyin, Qihe, and Juye were tested using 23 barley, oat, and wheat entries of the International Test Assortment for Defining Cereal Cyst Nematode Pathotypes. H. avenae populations from Tangyin, Qihe, and Juye were classified as pathotype Ha91, and H. filipjevi from Xuchang was classified as a new pathotype similar to pathotype West. Among 42 other winter wheat cultivars, 29 and 30 were differentially susceptible, 13 and 12 were differentially resistant to H. avenae and H. filipjevi, respectively. Three entries were resistant to both species, and three other entries were resistant to H. avenae and moderately resistant to H. filipjevi. Coating wheat seed with abamectin + isopycnic imidacloprid or methylene (bis) thiocyanate + thiamethoxam reduced the number of H. avenae and H. filipjevi cysts by 46 to 56%, increased wheat yield by 9 to 27%, and improved net income by 660 to 2,640 Chinese Yuan ha-1, respectively. Resistant wheat cultivars are scarce in China, and seed coating is considered the most suitable method for controlling CCNs in the North China Plain, where crop rotation cannot be practiced.

Genome-Wide Analysis Reveals Dynamic Epigenomic Differences in Soybean Response to Low-Phosphorus Stress.

Low-phosphorus (low-P) stress has a significant limiting effect on crop yield and quality. Although the molecular mechanisms of the transcriptional level responsible for the low-P stress response have been studied in detail, the underlying epigenetic mechanisms in gene regulation remain largely unknown. In this study, we evaluated the changes in DNA methylation, gene expression and small interfering RNAs (siRNAs) abundance genome-wide in response to low-P stress in two representative soybean genotypes with different P-efficiencies. The DNA methylation levels were slightly higher under low-P stress in both genotypes. Integrative methylation and transcription analysis suggested a complex regulatory relationship between DNA methylation and gene expression that may be associated with the type, region, and extent of methylation. Association analysis of low-P-induced differential methylation and gene expression showed that transcriptional alterations of a small part of genes were associated with methylation changes. Dynamic methylation alterations in transposable element (TE) regions in the CHH methylation context correspond with changes in the amount of siRNA under low-P conditions, indicating an important role of siRNAs in modulating TE activity by guiding CHH methylation in TE regions. Together, these results could help to elucidate the epigenetic regulation mechanisms governing the responses of plants to abiotic stresses.

Overexpression of the Wild Soybean R2R3-MYB Transcription Factor GsMYB15 Enhances Resistance to Salt Stress and Helicoverpa Armigera in Transgenic Arabidopsis.

Plant R2R3-MYB transcription factors (TFs) have been suggested to play crucial roles in the response to diverse abiotic and biotic stress factors but there is little molecular evidence of this role in soybean plants. In this work, we identified and functionally characterized an R2R3-MYB TF, namely, GsMYB15, from the wild soybean ED059. Protein and promoter sequence analysis indicated that GsMYB15 is a typical R2R3-MYB TF and contains multiple stress-related cis-elements in the promoter region. GsMYB15 is located in the nucleus and exhibits transcriptional activation activity. QPCR assays suggested that the expression of GsMYB15 could be induced by NaCl, insect attacks and defense-related hormones (MeJA and SA). Furthermore, GsMYB15 exhibited highest expression in pods compared to other tissues. Functional analysis of GsMYB15 demonstrated that overexpression of GsMYB15 could increase salt tolerance and enhance the resistance to H. armigera larvae in transgenic Arabidopsis plants. Moreover, overexpression of GsMYB15 also affected the expression levels of salt stress- and defense-related genes in the transgenic plants. Feeding with transgenic Arabidopsis plant leaves could significantly suppress the expression levels of immunity-related genes in H. armigera larvae. Overexpression of GsMYB15 also increased mesophyll cell levels in transgenic plants. Taken together, these results provide evidence that GsMYB15 is a positive regulator of salt stress tolerance and insect resistance in transformed Arabidopsis plants.

Genome-Wide Identification and Characterization of the GmSnRK2 Family in Soybean.

Sucrose non-fermenting-1 (SNF1)-related protein kinase 2s (SnRK2s) that were reported to be involved in the transduction of abscisic acid (ABA) signaling, play important roles in response to biotic and abiotic stresses in plants. Compared to the systemic investigation of SnRK2s in Arabidopsisthaliana and Oryza sativa, little is known regarding SnRK2s in soybean, which is one of the most important oil and protein crops. In the present study, we performed genome-wide identification and characterization of GmSnRK2s in soybean. In summary, 22 GmSnRK2s were identified and clustered into four groups. Phylogenetic analysis indicated the expansion of SnRK2 gene family during the evolution of soybean. Various cis-acting elements such as ABA Response Elements (ABREs) were identified and analyzed in the promoter regions of GmSnRK2s. The results of RNA sequencing (RNA-Seq) data for different soybean tissues showed that GmSnRK2s exhibited spatio-temporally specific expression patterns during soybean growth and development. Certain GmSnRK2s could respond to the treatments including salinity, ABA and strigolactones. Our results provide a foundation for the further elucidation of the function of GmSnRK2 genes in soybean.

Genome-wide binding analysis of the transcription activator ideal plant architecture1 reveals a complex network regulating rice plant architecture.

Ideal plant architecture1 (IPA1) is critical in regulating rice (Oryza sativa) plant architecture and substantially enhances grain yield. To elucidate its molecular basis, we first confirmed IPA1 as a functional transcription activator and then identified 1067 and 2185 genes associated with IPA1 binding sites in shoot apices and young panicles, respectively, through chromatin immunoprecipitation sequencing assays. The Squamosa promoter binding protein-box direct binding core motif GTAC was highly enriched in IPA1 binding peaks; interestingly, a previously uncharacterized indirect binding motif TGGGCC/T was found to be significantly enriched through the interaction of IPA1 with proliferating cell nuclear antigen promoter binding factor1 or promoter binding factor2. Genome-wide expression profiling by RNA sequencing revealed IPA1 roles in diverse pathways. Moreover, our results demonstrated that IPA1 could directly bind to the promoter of rice teosinte branched1, a negative regulator of tiller bud outgrowth, to suppress rice tillering, and directly and positively regulate dense and erect panicle1, an important gene regulating panicle architecture, to influence plant height and panicle length. The elucidation of target genes of IPA1 genome-wide will contribute to understanding the molecular mechanisms underlying plant architecture and to facilitating the breeding of elite varieties with ideal plant architecture.

Quantitative trait locus analysis for pod- and kernel-related traits in the cultivated peanut (Arachis hypogaea L.).

BACKGROUND: The cultivated peanut (Arachis hypogaea L.) is an important oil and food crop in the world. Pod- and kernel-related traits are direct factors involved in determining the yield of the peanut. However, the genetic basis underlying pod- and kernel-related traits in the peanut remained largely unknown, which hampered the improvement of peanut through marker-assisted selection. To understand the genetic basis underlying pod- and kernel-related traits in the peanut and provide more useful information for marker-assisted breeding, we conducted quantitative trait locus (QTL) analysis for pod length and width and seed length and width by use of two F2:3 populations derived from cultivar Fuchuan Dahuasheng × ICG 6375 (FI population) and cultivar Xuhua 13 × cultivar Zhonghua 6 (XZ population) in this study. RESULTS: Two genetic maps containing 347 and 228 polymorphic markers were constructed for FI and XZ populations respectively. In total, 39 QTLs explaining 1.25-26.11% of the phenotypic variations were detected in two populations. For the FI population, 26 QTLs were detected between the two environments, among which twelve were not mapped before. For the XZ population, thirteen QTLs were detected, among which eight were not reported before. One QTL for pod width was repeatedly mapped between the two populations. CONCLUSION: The QTL analyses for pod length and width and seed length and width were conducted in this study using two mapping populations. Novel QTLs were identified, which included two for pod length, four for pod width, five for seed length and one for seed width in the FI population, and three for pod length, three for pod width and two for seed width in the XZ population. Our results will be helpful for improving pod- and seed-related traits in peanuts through marker-assisted selection.

Whole-genome gene expression profiling revealed genes and pathways potentially involved in regulating interactions of soybean with cyst nematode (Heterodera glycines Ichinohe).

BACKGROUND: Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most devastating pathogen of soybean. Many gene expression profiling studies have been conducted to investigate the responses of soybean to the infection by this pathogen using primarily the first-generation soybean genome array that covered approximately 37,500 soybean transcripts. However, no study has been reported yet using the second-generation Affymetrix soybean whole-genome transcript array (Soybean WT array) that represents approximately 66,000 predicted soybean transcripts. RESULTS: In the present work, the gene expression profiles of two soybean plant introductions (PIs) PI 437654 and PI 567516C (both resistant to multiple SCN HG Types) and cultivar Magellan (susceptible to SCN) were compared in the presence or absence of the SCN inoculum at 3 and 8 days post-inoculation using the Soybean WT array. Data analysis revealed that the two resistant soybean lines showed distinctive gene expression profiles from each other and from Magellan not only in response to the SCN inoculation, but also in the absence of SCN. Overall, 1,413 genes and many pathways were revealed to be differentially regulated. Among them, 297 genes were constitutively regulated in the two resistant lines (compared with Magellan) and 1,146 genes were responsive to the SCN inoculation in the three lines, with 30 genes regulated both constitutively and by SCN. In addition to the findings similar to those in the published work, many genes involved in ethylene, protein degradation, and phenylpropanoid pathways were also revealed differentially regulated in the present study. GC-rich elements (e.g., GCATGC) were found over-represented in the promoter regions of certain groups of genes. These have not been observed before, and could be new defense-responsive regulatory elements. CONCLUSIONS: Different soybean lines showed different gene expression profiles in the presence and absence of the SCN inoculum. Both inducible and constitutive gene expression may contribute to resistance to multiple SCN HG Types in the resistant soybean PI lines. Ethylene, protein degradation, and phenylpropanoid pathways, as well as many other pathways reported previously, may play important roles in mediating the soybean-SCN interactions. The revealed genes, pathways, and promoter elements can be further explored to regulate or engineer soybean for resistance to SCN.

Identification and evaluation of quantitative trait loci underlying resistance to multiple HG types of soybean cyst nematode in soybean PI 437655.

KEY MESSAGE: We performed QTL analysis for SCN resistance in PI 437655 in two mapping populations, characterized CNV of Rhg1 through whole-genome resequencing and evaluated the effects of QTL pyramiding to enhance resistance. Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is one of the most serious pests of soybean worldwide. PI 437655 has broader resistance to SCN HG types than PI 88788. The objectives of this study were to identify quantitative trait loci (QTL) underlying SCN resistance in PI 437655, and to evaluate the QTL for their contribution to SCN resistance. Two F6:7 recombinant inbred line populations, derived from cv. Williams 82 × PI 437655 and cv. Hutcheson × PI 437655 crosses, were evaluated for resistance to SCN HG types 1.2.5.7 (PA2), 0 (PA3), 1.3.5.6.7 (PA14), and 1.2.3.4.5.6.7 (LY2). The 1,536 SNP array was used to genotype the mapping populations and construct genetic linkage maps. Two significant QTL were consistently mapped on chromosomes (Chr.) 18 and 20 in these two populations. One QTL on Chr. 18, which corresponds to the known Rhg1 locus, contributed resistance to SCN HG types 1.2.5.7, 0, 1.3.5.6.7, and 1.2.3.4.5.6.7 (PA2, PA3, PA14, and LY2, respectively). Copy number variation (CNV) analysis by whole-genome resequencing showed that PI 437655 and PI 88788 had similar CNV at the Rhg1 locus. The QTL on Chr. 20 contributed resistance to SCN HG types 1.3.5.6.7 (PA14) and 1.2.3.4.5.6.7 (LY2). Evaluation of both QTL showed that pyramiding of Rhg1 and the QTL on Chr. 20 significantly improved the resistance to SCN HG types 1.3.5.6.7 (PA14) and 1.2.3.4.5.6.7 (LY2) in both populations. Our studies provided useful information for deploying PI 437655 as a donor for SCN resistance in soybean breeding through marker-assisted selection.

The soybean ubiquitin-proteasome system: Current knowledge and future perspective.

Increasing soybean [Glycine max (L.) Merr.] yield has become a worldwide scientific problem in the world. Many studies have shown that ubiquitination plays a key role in stress response and yield formation. In the UniProtKB database, 2,429 ubiquitin-related proteins were predicted in soybean, however, <20 were studied. One key way to address this lack of progress in increasing soybean yield will be a deeper understanding of the ubiquitin-proteasome system (UPS) in soybean. In this review, we summarized the current knowledge about soybean ubiquitin-related proteins and discussed the method of combining phenotype, mutant library, transgenic system, genomics, and proteomics approaches to facilitate the exploration of the soybean UPS. We also proposed the strategy of applying the UPS in soybean improvement based on related studies in model plants. Our review will be helpful for soybean scientists to learn current research progress of the soybean UPS and further lay a theoretical reference for the molecular improvement of soybean in future research by use of this knowledge.

AtMYBS1 negatively regulates heat tolerance by directly repressing the expression of MAX1 required for strigolactone biosynthesis in Arabidopsis.

Heat stress caused by global warming requires the development of thermotolerant crops to sustain yield. It is necessary to understand the molecular mechanisms that underlie heat tolerance in plants. Strigolactones (SLs) are a class of carotenoid-derived phytohormones that regulate plant development and responses to abiotic or biotic stresses. Although SL biosynthesis and signaling processes are well established, genes that directly regulate SL biosynthesis have rarely been reported. Here, we report that the MYB-like transcription factor AtMYBS1/AtMYBL, whose gene expression is repressed by heat stress, functions as a negative regulator of heat tolerance by directly inhibiting SL biosynthesis in Arabidopsis. Overexpression of AtMYBS1 led to heat hypersensitivity, whereas atmybs1 mutants displayed increased heat tolerance. Expression of MAX1, a critical enzyme in SL biosynthesis, was induced by heat stress and downregulated in AtMYBS1-overexpression (OE) plants but upregulated in atmybs1 mutants. Overexpression of MAX1 in the AtMYBS1-OE background reversed the heat hypersensitivity of AtMYBS1-OE plants. Loss of MAX1 function in the atmyb1 background reversed the heat-tolerant phenotypes of atmyb1 mutants. Yeast one-hybrid assays, chromatin immunoprecipitation‒qPCR, and transgenic analyses demonstrated that AtMYBS1 directly represses MAX1 expression through the MYB binding site in the MAX1 promoter in vivo. The atmybs1d14 double mutant, like d14 mutants, exhibited hypersensitivity to heat stress, indicating the necessary role of SL signaling in AtMYBS1-regulated heat tolerance. Our findings provide new insights into the regulatory network of SL biosynthesis, facilitating the breeding of heat-tolerant crops to improve crop production in a warming world.

Typification and Nomenclature Notes on Twenty-Nine Names in Asparagus (Asparagaceae).

Nomenclatural types for twenty-nine names belonging to the genus Asparagus are typified and discussed. The following names are lectotypified: A. altiscandens Engl. & Gilg, A. altissimus Munby, A. baumii Engl. & Gilg, A. benguellensis Baker, A. burchellii Baker, A. curillus Buch.-Ham. ex Roxb., A. deflexus Baker, A. duchesnei L.Linden, A. equisetoides Welw. ex Baker, A. fasciculatus Thunb., A. griffithii, Baker, A. homblei De Wild., A. kaessneri De Wild., A. lecardii De Wild., A. longicladus N.E.Br., A. longiflorus Franch., A. monophyllus Baker, A. palaestinus Baker, A. pastorianus Webb & Berthel., A. persicus Baker, A. poissonii H.Perrier, A. psilurus Welw. ex Baker, A. ritschardii De Wild., A. sapinii De Wild., A. scandens Thunb., A. schumanianus Schltr. ex H.Perrier, A. stellatus Baker, A. subfalcatus De Wild., and A. undulatus (L.f.) Thunb. (synonym of Dracaena undulata L.f.). A new name, Asparagus neofasciculatus, is proposed as a replacement name for A. fasciculatus Thunb., which is an illegitimate later homonym of A. fasciculatus R.Br. The original protologue of these names and the original materials are evaluated. Nomenclature remarks discussing the selection of type specimens are given for each name, and known isotypes or isolectotypes are also cited. This information could be utilized as a reference for future taxonomic and systematic studies on Asparagus around the world.

Blue light receptor CRY1 regulates HSFA1d nuclear localization to promote plant thermotolerance.

Temperature increases as light intensity rises, but whether light signals can be directly linked to high temperature response in plants is unclear. Here, we find that light pre-treatment enables plants to survive better under high temperature, designated as light-induced thermotolerance (LIT). With short-term light treatment, plants induce light-signaling pathway genes and heat shock genes. Blue light photoreceptor cryptochrome 1 (CRY1) is required for LIT. We also find that CRY1 physically interacts with the heat shock transcription factor A1d (HsfA1d) and that HsfA1d is involved in thermotolerance under light treatment. Furthermore, CRY1 promotes HsfA1d nuclear localization through importin alpha 1 (IMPα1). Consistent with this, CRY1 shares more than half of the chromatin binding sites with HsfA1d. Mutation of CRY1 (cry1-304) diminishes a large number of HsfA1d binding sites that are shared with CRY1. We present a model where, by coupling light sensing to high-temperature stress, CRY1 confers thermotolerance in plants via HsfA1d.