Genome-wide identification and expression analysis of the MADS-box gene family during female and male flower development in Juglans mandshurica

MADS-Box Family Genes in Lagerstroemia indica and Their Involvement in Flower Development

MADS-box is a key transcription factor regulating the transition to flowering and flower development. Lagerstroemia indica 'Xiang Yun' is a new cultivar of crape myrtle characterized by its non-fruiting nature. To study the molecular mechanism underlying the non-fruiting characteristics of 'Xiang Yun', 82 MADS-box genes were identified from the genome of L. indica. The physicochemical properties of these genes were examined using bioinformatics methods, and their expression as well as endogenous hormone levels at various stages of flower development were analyzed. The results showed that LiMADS genes were primarily classified into two types: type I and type II, with the majority being type II that contained an abundance of cis-acting elements in their promoters. By screening nine core proteins by predicted protein interactions and performing qRT-PCR analysis as well as in combination with transcriptome data, we found that the expression levels of most MADS genes involved in flower development were significantly lower in 'Xiang Yun' than in the wild type 'Hong Ye'. Hormonal analysis indicated that 'Xiang Yun' had higher levels of iP, IPR, TZR, and zeatin during its early stages of flower development than 'Hong Ye', whereas the MeJA content was substantially lower at the late stage of flower development of 'Hong Ye'. Finally, correlation analysis showed that JA, IAA, SA, and TZR were positively correlated with the expression levels of most type II genes. Based on these analyses, a working model for the non-fruiting 'Xiang Yun' was proposed. During the course of flower development, plant hormone response pathways may affect the expression of MADS genes, resulting in their low expression in flower development, which led to the abnormal development of the stamen and embryo sac and ultimately affected the fruiting process of 'Xiang Yun'.

Genome-Wide Identification of the MADS-Box Gene Family during Male and Female Flower Development in Chayote (Sechium edule)

The MADS-box gene plays an important role in plant growth and development. As an important vegetable of Cucurbitaceae, chayote has great edible and medicinal value. So far, there is little molecular research on chayote, and there are no reports on the MADS-box transcription factor of chayote. In this study, the MADS-box gene family of chayote was analyzed for the first time, and a total of 70 MADS-box genes were identified, including 14 type I and 56 type II MICK MADS genes. They were randomly distributed on 13 chromosomes except for chromosome 11. The light response element, hormone response element and abiotic stress response element were found in the promoter region of 70 MADS genes, indicating that the MADS gene can regulate the growth and development of chayote, resist abiotic stress, and participate in hormone response; GO and KEGG enrichment analysis also found that SeMADS genes were mainly enriched in biological regulation and signal regulation, which further proved the important role of MADS-box gene in plant growth and development. The results of collinearity showed that segmental duplication was the main driving force of MADS gene expansion in chayote. RNA-seq showed that the expression levels of SeMADS06, SeMADS13, SeMADS26, SeMADS28, SeMADS36 and SeMADS37 gradually increased with the growth of chayote, indicating that these genes may be related to the development of root tubers of 'Tuershao'. The gene expression patterns showed that 12 SeMADS genes were specifically expressed in the male flower in 'Tuershao' and chayote. In addition, SeMADS03 and SeMADS52 may be involved in regulating the maturation of male flowers of 'Tuershao' and chayote. SeMADS21 may be the crucial gene in the development stage of the female flower of 'Tuershao'. This study laid a theoretical foundation for the further study of the function of the MADS gene in chayote in the future.

Genome-Wide Identification and Characterization of Copper Chaperone for Superoxide Dismutase (CCS) Gene Family in Response to Abiotic Stress in Soybean

Copper Chaperone For Superoxide Dismutase (CCS) genes encode copper chaperone for Superoxide dismutase (SOD) and dramatically affect the activity of SOD through regulating copper delivery from target to SOD. SOD is the effective component of the antioxidant defense system in plant cells to reduce oxidative damage by eliminating Reactive oxygen species (ROS), which are produced during abiotic stress. CCS might play an important role in abiotic stress to eliminate the damage caused by ROS, however, little is known about CCS in soybean in abiotic stress regulation. In this study, 31 GmCCS gene family members were identified from soybean genome. These genes were classified into 4 subfamilies in the phylogenetic tree. Characteristics of 31 GmCCS genes including gene structure, chromosomal location, collinearity, conserved domain, protein motif, cis-elements, and tissue expression profiling were systematically analyzed. RT-qPCR was used to analyze the expression of 31 GmCCS under abiotic stress, and the results showed that 5 GmCCS genes(GmCCS5, GmCCS7, GmCCS8, GmCCS11 and GmCCS24) were significantly induced by some kind of abiotic stress. The functions of these GmCCS genes in abiotic stress were tested using yeast expression system and soybean hairy roots. The results showed that GmCCS7/GmCCS24 participated in drought stress regulation. Soybean hairy roots expressing GmCCS7/GmCCS24 showed improved drought stress tolerance, with increased SOD and other antioxidant enzyme activities. The results of this study provide reference value in-depth study CCS gene family, and important gene resources for the genetic improvement of soybean drought stress tolerance.