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.

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.

Quite a few studies have been conducted to improve the Agrobacterium-mediated transformation of pineapple, which is the second most important commercial tropical fruit crop worldwide. However, pineapple transformation remains challenging, due to technical difficulties, the lengthy regeneration process, and a high labor requirement. There have not been any studies specifically addressing the introduction of GFP-tagged genes into pineapples through Agrobacterium-mediated transformation, which would enable easy, non-destructive expression detection. It would also allow expression localization at the organelle level, which is not possible with GUS a reporter gene that encodes β-glucuronidase or a herbicide resistance reporter gene. Here, we report a method for the introduction of GFP-tagged genes into pineapples through Agrobacterium-mediated transformation. We used embryonic calli for transformation, and plants were regenerated through somatic embryogenesis. In this study, we optimized the incubation time for Agrobacterium infection, the co-cultivation time, the hygromycin concentration for selection, and the callus growth conditions after selection. Our strategy reduced the time required to obtain transgenic plants from 7.6 months to 6.1 months. The expression of GFP-tagged AcWRKY28 was observed in the nuclei of transgenic pineapple root cells. This method allows easy, non-destructive expression detection of transgenic constructs at the organelle level. These findings on pineapple transformation will help accelerate pineapple molecular breeding efforts to introduce new desirable traits.

Background: Calcium-dependent protein kinase (CPK) is one of the main Ca²⁺ combined protein kinase that play significant roles in plant growth, development and response to multiple stresses. Despite an important member of the stress responsive gene family, little is known about the evolutionary history and expression patterns of CPK genes in pineapple. Results: Herein, we identified and characterized 17 AcoCPK genes from pineapple genome, which were unevenly distributed across eight chromosomes. Based on the gene structure and phylogenetic tree analyses, AcoCPKs were divided into four groups with conserved domain. Synteny analysis identified 7 segmental duplication events of AcoCPKs and 5 syntenic blocks of CPK genes between pineapple and Arabidopsis, and 8 between pineapple and rice. Expression pattern of different tissues and development stages suggested that several genes are involved in the functional development of plants. Different expression levels under various abiotic stresses also indicated that the CPK family underwent functional divergence during long-term evolution. AcoCPK1, AcoCPK3 and AcoCPK6, which were repressed by the abiotic stresses, were shown to be function in regulating pathogen resistance. Conclusions: 17 AcoCPK genes from pineapple genome were identified. Our analyses provide an important foundation for understanding the potential roles of AcoCPKs in regulating pineapple response to biotic and abiotic stresses

Terpinen-4-ol (T-4-O) is an important component of tea tree oil and has anti-inflammatory effects. Currently, there are very few studies on the mechanisms by which T-4-O improves lipopolysaccharide (LPS)-induced macrophage inflammation. In this study, LPS-stimulated mouse RAW264.7 macrophages were used as a model to analyze the effects of T-4-O on macrophage inflammatory factors and related metabolic pathways in an inflammatory environment. The results showed that T-4-O significantly decreased the expression levels of inflammatory cytokines induced by LPS. Cellular metabolism results showed that T-4-O significantly decreased the ratio of the extracellular acidification rate and oxygen consumption rate. Non-targeted metabolomics results showed that T-4-O mainly affected glutamine and glutamate metabolism and glycine, serine, and threonine metabolic pathways. qPCR results showed that T-4-O increased the transcript levels of GLS and GDH and promoted glutamine catabolism. Western blotting results showed that T-4-O inhibited the mTOR and IκB, thereby decreasing NF-κB activity. The overall results showed that T-4-O inhibited mTOR phosphorylation to promote glutamine metabolism and increased cell oxidative phosphorylation levels, thereby inhibiting the expression of LPS-induced inflammatory cytokines.