Search

Plant trehalose has been regarded to play a key role in various biological processes during the growth and development stages. Trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) are two important enzymes for the synthesis of plant trehalose. Up till now, the TPS and TPP gene families have been identified and characterized in numerous higher plant species, but are rarely recorded in peanuts (Arachis hypogaea). In this study, a comprehensive search was performed to identify all putative TPS and TPP proteins in the peanut genome using Arabidopsis TPS and TPP proteins as queries. We then analyzed the characteristics of TPS and TPP members, including physic-chemical parameters, subcellular localization, phylogeny relationships, gene duplication, and expression patterns by various computational tools. As a result, a total of 17 ArahyTPS and 15 ArahyTPP genes were identified and annotated in the peanut genome, which was expanded by segmental duplication events. Our Neighbor-Joining based phylogenetic tree indicated that the ArahyTPS and ArahyTPP proteins could be categorized into three and two major branches. Gene structures and protein features analysis exhibited that the ArahyTPS and ArahyTPP proteins shared high structural and functional similarities. Based on previous RNA-Seq datasets, a majority of the ArahyTPS and ArahyTPP genes were found to specifically express in at least one major organ/tissue during the growth and development. This work will not only lead to a solid foundation on reveal the potential roles of ArahyTPS and ArahyTPP gene families in peanuts but also provide evidence to related trehalose research in other higher plant species.

Eucalypts are the most planted trees worldwide, but most of them are frost sensitive. Overexpressing transcription factors for CRT-repeat binding factors (CBFs) in transgenic Eucalyptus confer cold resistance both in leaves and stems. While wood plays crucial roles in trees and is affected by environmental cues, its potential role in adaptation to cold stress has been neglected. Here, we addressed this question by investigating the changes occurring in wood in response to the overexpression of two CBFs, taking advantage of available transgenic Eucalyptus lines. We performed histological, biochemical, and transcriptomic analyses on xylem samples. CBF ectopic expression led to a reduction of both primary and secondary growth, and triggered changes in xylem architecture with smaller and more frequent vessels and fibers exhibiting reduced lumens. In addition, lignin content and syringyl/guaiacyl (S/G) ratio increased. Consistently, many genes of the phenylpropanoid and lignin branch pathway were upregulated. Most of the features of xylem remodeling induced by CBF overexpression are reminiscent of those observed after long exposure of Eucalyptus trees to chilling temperatures. Altogether, these results suggest that CBF plays a central role in the cross-talk between response to cold and wood formation and that the remodeling of wood is part of the adaptive strategies to face cold stress.