Abstract
Cold stress restricts peanut (Arachis hypogaea L.) growth, development, and yield. However, the specific mechanism of cold tolerance in peanut remains unknown. Here, the comparative physiological, transcriptomic, and lipidomic analyses of cold tolerant variety NH5 and cold sensitive variety FH18 at different time points of cold stress were conducted to fill this gap. Transcriptomic analysis revealed lipid metabolism including membrane lipid and fatty acid metabolism may be a significant contributor in peanut cold tolerance, and 59 cold-tolerant genes involved in lipid metabolism were identified. Lipidomic data corroborated the importance of membrane lipid remodeling and fatty acid unsaturation. It indicated that photosynthetic damage, resulted from the alteration in fluidity and integrity of photosynthetic membranes under cold stress, were mainly caused by markedly decreased monogalactosyldiacylglycerol (MGDG) levels and could be relieved by increased digalactosyldiacylglycerol (DGDG) and sulfoquinovosyldiacylglycerol (SQDG) levels. The upregulation of phosphatidate phosphatase (PAP1) and phosphatidate cytidylyltransferase (CDS1) inhibited the excessive accumulation of PA, thus may prevent the peroxidation of membrane lipids. In addition, fatty acid elongation and fatty acid β-oxidation were also worth further studied in peanut cold tolerance. Finally, we constructed a metabolic model for the regulatory mechanism of peanut cold tolerance, in which the advanced lipid metabolism system plays a central role. This study lays the foundation for deeply analyzing the molecular mechanism and realizing the genetic improvement of peanut cold tolerance.
Highlights
Peanut (Arachis hypogaea L.), one of the most important grain legumes and a source of edible oils and proteins, is cultivated in tropical and subtropical regions of the world (Huang et al, 2019)
The magnitude of the decreases of FH18 were greater than those of NH5, especially for shoot (including leaves) fresh weight (SFW), shoot dry weight (SDW), and root dry weight (RDW), which suggested that peanut cultivar FH18 was more sensitive to 6°C temperature exposure than NH5 and that the leaves and shoots of plants were more susceptible to cold stress than other tissues
Transcriptional profiling of two peanut cultivars indicated that lipid metabolism may play a central role in peanut cold tolerance; we further focused our analyses on the changes in transcription activity of a compiled list of 651 genes involved in lipid metabolism (Table S13), which were identified based on a homology search to known lipid metabolism genes in the higher model plant Arabidopsis thaliana reported in Aralip website
Summary
Peanut (Arachis hypogaea L.), one of the most important grain legumes and a source of edible oils and proteins, is cultivated in tropical and subtropical regions of the world (Huang et al, 2019). With increasing demand for peanuts, plantings have rapidly expanded in high-latitude areas such as northeast China (Bai et al, 2019). The heat condition in northeast China is poor and the extreme climate events such as low temperature caused by global climate change occur frequently, severely restricting peanut growth, development, productivity, and geographical distribution in temperate and high-elevation areas (Xiao and Song, 2011; Chen N. et al, 2014). In addition to morphological and physiological changes, cold stress can lead to a series of complex signal transduction and transcriptional rearrangements Most temperate or hardy plants have evolved precise mechanisms to survive low temperature. Understanding the specific mechanism of peanut cold tolerance is the critical first step toward providing targets for genetic engineering of cold-tolerant peanut germplasm
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
