Soybean, a major legume crop native to East Asia, presents a wealth of resources for utilization. The basic leucine zipper (bZIP) transcription factors play important roles in various biological processes including developmental regulation and responses to environmental stress stimuli. Currently, little information is available regarding the bZIP family in the legume crop soybean. Using a genome-wide domain analysis, we identified 160 GmbZIP genes in soybean genome, named from GmbZIP1 to GmbZIP160. These 160GmbZIP genes, distributed unevenly across 20 chromosomes, were grouped into 12 subfamilies based on phylogenetic analysis. Gene structure and conserved motif analyses showed that GmbZIP within the same subfamily shared similar intron-exon organizations and motif composition. Syntenic and phylogenetic analyses identified 40 Arabidopsis bZIP genes and 83 soybean bZIP genes as orthologs. By investigating the expression profiling of GmbZIP in different tissues and under drought and flooding stresses, we showed that a majority of GmbZIP (83.44%) exhibited transcript abundance in all examined tissues and 75.6% displayed transcript changes after drought and flooding treatment, suggesting that GmbZIP may play a broad role in soybean development and response to water stress. One hundred sixty GmbZIP genes were identified in soybean genome. Our results provide insights for the evolutionary history of bZIP family in soybean and shed light on future studies on the function of bZIP genes in response to water stress in soybean.

Soybean (Glycine max), as an important oilseed crop, is constantly threatened by abiotic stress, including that caused by salinity and drought. bZIP transcription factors (TFs) are one of the largest TF families and have been shown to be associated with various environmental-stress tolerances among species; however, their function in abiotic-stress response in soybean remains poorly understood. Here, we characterized the roles of soybean transcription factor GmbZIP15 in response to abiotic stresses. The transcript level of GmbZIP15 was suppressed under salt- and drought-stress conditions. Overexpression of GmbZIP15 in soybean resulted in hypersensitivity to abiotic stress compared with wild-type (WT) plants, which was associated with lower transcript levels of stress-responsive genes involved in both abscisic acid (ABA)-dependent and ABA-independent pathways, defective stomatal aperture regulation, and reduced antioxidant enzyme activities. Furthermore, plants expressing a functional repressor form of GmbZIP15 exhibited drought-stress resistance similar to WT. RNA-seq and qRT-PCR analyses revealed that GmbZIP15 positively regulates GmSAHH1 expression and negatively regulates GmWRKY12 and GmABF1 expression in response to abiotic stress. Overall, these data indicate that GmbZIP15 functions as a negative regulator in response to salt and drought stresses.

As Ca2+ sensors and effectors, calcium-dependent protein kinases (CDPKs) play important roles in plant growth, development, and response to environmental cues. However, no CDPKs have been characterized in Capsicum annuum thus far. Herein, a genome wide comprehensive analysis of genes encoding CDPKs and CDPK-related protein kinases (CRKs) was performed in pepper, a total of 31 CDPK genes and five closely related kinase genes were identified, which were phylogenetically divided into four distinct subfamilies and unevenly distributed across nine chromosomes. Conserved sequence and exon-intron structures were found to be shared by pepper CDPKs within the same subfamily, and the expansion of the CDPK family in pepper was found to be due to segmental duplication events. Five CDPKs in the C. annuum variety CM334 were found to be mutated in the Chiltepin variety, and one CDPK present in CM334 was lost in Chiltepin. The majority of CDPK and CRK genes were expressed in different pepper tissues and developmental stages, and 10, 12, and 8 CDPK genes were transcriptionally modified by salt, heat, and Ralstonia solanacearum stresses, respectively. Furthermore, these genes were found to respond specifically to one stress as well as respond synergistically to two stresses or three stresses, suggesting that these CDPK genes might be involved in the specific or synergistic response of pepper to salt, heat, and R. solanacearum. Our results lay the foundation for future functional characterization of pepper CDPK and its closely related gene families.

Background: Dehydration responsive element-binding (DREB) transcription factors play a crucial role in plant growth, development and stress responses. Although DREB genes have been characterized in many plant species, genome-wide identification of the DREB gene family has not yet been reported in pineapple (Ananas comosus (L.) Merr.). Results: Using comprehensive genome-wide screening, we identified 20 AcoDREB genes on 14 chromosomes. These were categorized into five subgroups. AcoDREBs within a group had similar gene structures and domain compositions. Using gene structure analysis, we showed that most AcoDREB genes (75%) lacked introns, and that the promoter regions of all 20 AcoDREB genes had at least one stress response-related cis-element. We identified four genes with high expression levels and six genes with low expression levels in all analyzed tissues. We detected expression changes under abiotic stress for eight selected AcoDREB genes. Conclusions: This report presents the first genome-wide analysis of the DREB transcription factor family in pineapple. Our results provide preliminary data for future functional analysis of AcoDREB genes in pineapple, and useful information for developing new pineapple varieties with key agronomic traits such as stress tolerance.

Intricate spatial restriction of tasiR-ARF biogenesis, together with tasiR-ARF mobility, enables cell-cell communication in MMC differentiation.

The basic leucine zipper (bZIP) is a plant-specific transcription factor family that plays crucial roles in response to biotic and abiotic stresses. However, little is known about the function of bZIP genes in soybean. In this study, we isolated a bZIP gene, GmbZIP19, from soybean. A subcellular localization study of GmbZIP19 revealed its nucleus localization. We showed that GmbZIP19 expression was significantly induced by ABA (abscisic acid), JA (jasmonic acid) and SA (salicylic acid), but reduced under salt and drought stress conditions. Further, GmbZIP19 overexpression Arabidopsis lines showed increased resistance to S. sclerotiorum and Pseudomonas syringae associated with upregulated ABA-, JA-, ETH- (ethephon-)and SA-induced marker genes expression, but exhibited sensitivity to salt and drought stresses in association with destroyed stomatal closure and downregulated the salt and drought stresses marker genes’ expression. We generated a soybean transient GmbZIP19 overexpression line, performed a Chromatin immunoprecipitation assay and found that GmbZIP19 bound to promoters of ABA-, JA-, ETH-, and SA-induced marker genes in soybean. The yeast one-hybrid verified the combination. The current study suggested that GmbZIP19 is a positive regulator of pathogen resistance and a negative regulator of salt and drought stress tolerance.