Mingli Shen

Plant mitochondrial genomes exist and function in a special way, this third-kind genetic material is essential for plant growth and development. However, i

Heat shock factors (HSFs) are the key regulators of heat stress responses and play pivotal roles in tissue development and the temperature-induced regulation of secondary metabolites. In order to elucidate the roles of HSFs in Cymbidium ensifolium, we conducted a genome-wide identification of CeHSF genes and predicted their functions based on their structural features and splicing patterns. Our results revealed 22 HSF family members, with each gene containing more than one intron. According to phylogenetic analysis, 59.1% of HSFs were grouped into the A subfamily, while subfamily HSFC contained only two HSFs. And the HSF gene families were differentiated evolutionarily between plant species. Two tandem repeats were found on Chr02, and two segmental duplication pairs were observed on Chr12, Chr17, and Chr19; this provided evidence for whole-genome duplication (WGD) events in C. ensifolium. The core region of the promoter in most CeHSF genes contained cis-acting elements such as AP2/ERF and bHLH, which were associated with plant growth, development, and stress responses. Except for CeHSF11, 14, and 19, each of the remaining CeHSFs contained at least one miRNA binding site. This included binding sites for miR156, miR393, and miR319, which were responsive to temperature and other stresses. The HSF gene family exhibited significant tissue specificity in both vegetative and floral organs of C. ensifolium. CeHSF13 and CeHSF15 showed relatively significant expression in flowers compared to other genes. During flower development, CeHSF15 exhibited markedly elevated expression in the early stages of flower opening, implicating critical regulatory functions in organ development and floral scent-related regulations. During the poikilothermic treatment, CeHSF14 was upregulated over 200-fold after 6 h of heat treatment. CeHSF13 and CeHSF14 showed the highest expression at 6 h of low temperature, while the expression of CeHSF15 and CeHSF21 continuously decreased at a low temperature. The expression patterns of CeHSFs further confirmed their role in responding to temperature stress. Our study may help reveal the important roles of HSFs in plant development and metabolic regulation and show insight for the further molecular design breeding of C. ensifolium.

Auxin Response Factors (ARFs) mediate auxin signaling and govern diverse biological processes. However, a comprehensive analysis of the ARF gene family and identification of their key regulatory functions have not been conducted in Melastoma dodecandrum, leading to a weak understanding of further use and development for this functional shrub. In this study, we successfully identified a total of 27 members of the ARF gene family in M. dodecandrum and classified them into Class I–III. Class II–III showed more significant gene duplication than Class I, especially for MedARF16s. According to the prediction of cis-regulatory elements, the AP2/ERF, BHLH, and bZIP transcription factor families may serve as regulatory factors controlling the transcriptional pre-initiation expression of MedARF. Analysis of miRNA editing sites reveals that miR160 may play a regulatory role in the post-transcriptional expression of MeARF. Expression profiles revealed that more than half of the MedARFs exhibited high expression levels in the stem compared to other organs. While there are some specific genes expressed only in flowers, it is noteworthy that MedARF16s, MedARF7A, and MedARF9B, which are highly expressed in stems, also demonstrate high expressions in other organs of M. dodecandrum. Further hormone treatment experiments revealed that these MedARFs were sensitive to auxin changes, with MedARF6C and MedARF7A showing significant and rapid changes in expression upon increasing exogenous auxin. In brief, our findings suggest a crucial role in regulating plant growth and development in M. dodecandrum by responding to changes in auxin. These results can provide a theoretical basis for future molecular breeding in Myrtaceae.

Jasmine, a recently domesticated shrub, is renowned for its use as a key ingredient in floral tea and its captivating fragrance, showcasing significant ornamental and economic value. When cultivated to subtropical zone, a significant abiotic stress adaptability occurs among different jasmine varieties, leading to huge flower production changes and plantlet survival. The bZIP transcription factors (TFs) are reported to play indispensable roles in abiotic stress tolerance. Here, we performed a genome-level comparison of bZIPs using three-type jasmine genomes. Based on their physicochemical properties, conserved motif analysis and phylogenetic analysis, about 63 bZIP genes were identified and clustered in jasmine genomes, noting a difference of one member compared to the other two types of jasmines. The HTbZIP genes were categorized into 12 subfamilies compared with A. thaliana. In cis-acting element analysis, all genes contained light-responsive elements. The abscisic acid response element (ABRE) was the most abundant in HTbZIP62 promoter, followed by HTbZIP33. Tissue-specific genes of the bZIPs may play a crucial role in regulating the development of jasmine organs and tissues, with HTbZIP36 showing the most significant expressions in roots. Combined with complicated protein interactions, HTbZIP62 and HTbZIP33 might play a crucial role in the ABA signaling pathway and stress tolerance. Combined with RT-qPCR analysis, SJbZIP37/57/62 were more sensitive to ABA response genes compared with other bZIPs in DJ amd HT genomes. Our findings provide a useful resource for further research on the regulation of key genes to improve abiotic stress tolerance in jasmine.