Evolution and Stress Responses of CLO Genes and Potential Function of the GhCLO06 Gene in Salt Resistance of Cotton

Roles of S-Adenosylmethionine and Its Derivatives in Salt Tolerance of Cotton

Salinity is a major abiotic stress that restricts cotton growth and affects fiber yield and quality. Although studies on salt tolerance have achieved great progress in cotton since the completion of cotton genome sequencing, knowledge about how cotton copes with salt stress is still scant. S-adenosylmethionine (SAM) plays important roles in many organelles with the help of the SAM transporter, and it is also a synthetic precursor for substances such as ethylene (ET), polyamines (PAs), betaine, and lignin, which often accumulate in plants in response to stresses. This review focused on the biosynthesis and signal transduction pathways of ET and PAs. The current progress of ET and PAs in regulating plant growth and development under salt stress has been summarized. Moreover, we verified the function of a cotton SAM transporter and suggested that it can regulate salt stress response in cotton. At last, an improved regulatory pathway of ET and PAs under salt stress in cotton is proposed for the breeding of salt-tolerant varieties.

A computational study on the structure-function relationships of plant caleosins

Plant cells store energy in oil bodies constructed by structural proteins such as oleosins and caleosins. Although oil bodies usually accumulate in the seed and pollen of plants, caleosins are present in various organs and organelles. This issue, coupled with the diverse activities of caleosins, complicates the description of these oleo-proteins. Therefore, the current article proposes a new classification based on the bioinformatics analysis of the transmembrane topology of caleosins. Accordingly, the non-membrane class are the most abundant and diverse caleosins, especially in lower plants. Comparing the results with other reports suggests a stress response capacity for these caleosins. However, other classes play a more specific role in germination and pollination. A phylogenetic study also revealed two main clades that were significantly different in terms of caleosin type, expression profile, molecular weight, and isoelectric point (P < 0.01). In addition to the biochemical significance of the findings, predicting the structure of caleosins is necessary for constructing oil bodies used in the food and pharmaceutical industries.

A Comprehensive Analysis of the DUF4228 Gene Family in Gossypium Reveals the Role of GhDUF4228-67 in Salt Tolerance

Soil salinization conditions seriously restrict cotton yield and quality. Related studies have shown that the DUF4228 proteins are pivotal in plant resistance to abiotic stress. However, there has been no systematic identification and analysis of the DUF4228 gene family in cotton and their role in abiotic stress. In this study, a total of 308 DUF4228 genes were identified in four Gossypium species, which were divided into five subfamilies. Gene structure and protein motifs analysis showed that the GhDUF4228 proteins were conserved in each subfamily. In addition, whole genome duplication (WGD) events and allopolyploidization might play an essential role in the expansion of the DUF4228 genes. Besides, many stress-responsive (MYB, MYC) and hormone-responsive (ABA, MeJA) related cis-elements were detected in the promoters of the DUF4228 genes. The qRT-PCR results showed that GhDUF4228 genes might be involved in the response to abiotic stress. VIGS assays and the measurement of relative water content (RWC), Proline content, POD activity, and malondialdehyde (MDA) content indicated that GhDUF4228-67 might be a positive regulator of cotton response to salt stress. The results in this study systematically characterized the DUF4228s in Gossypium species and will provide helpful information to further research the role of DUF4228s in salt tolerance.