Pretreatment of NaCl enhances the drought resistance of cotton by regulating the biosynthesis of carotenoids and abscisic acid

Abstract

Drought stress is one of the abiotic stresses that limits crop production and greatly affects crop yield. Enhancement of plant stress resistance by NaCl pretreatment has been reported, but the mechanism by which NaCl pretreatment activates cotton stress resistance remains unclear. In this study, upland cotton (Gossypium hirsutum cv H177) was used as the material to conducted the treatments with three replications: 0 Mm NaCl + 0% PEG6000 (Polyethylene glycol), 0 mM NaCl + 15% PEG6000, 50 mM NaCl + 15% PEG6000 to explore the molecular mechanism by which NaCl improves the drought tolerance of cotton. The results showed that pretreatment with 50 mM NaCl could alleviate the adverse effects of PEG on cotton seeds while promoting the elongation of root length. RNA-seq showed that NaCl specifically induced the expression of carotenoid-related genes. By silencing the upstream gene GHLUT2 of lutein synthesis, it was found that the chlorophyll of silenced plants decreased, and leaf wilting was more sensitive to drought. We found that NaCl enhanced the drought resistance of cotton by regulating genes related to the carotenoid and abscisic acid downstream synthesis pathways. This study provides a new reference for the study of drought resistance in cotton and a theoretical basis for the molecular breeding of cotton.

GhLCYε-3 characterized as a lycopene cyclase gene responding to drought stress in cotton

“…PEG6000 (Solarbio,Beijing) served as the standard for simulating drought conditions [19] . The treatment concentration was set at 15% PEG6000 and the processing time was 3 days, based on our previous research results [15] . The 12 materials are drought-tolerant and are preserved by the Institute of Cotton Research of Chinese Academy of Agricultural Sciences.…”

“…At the cellular level, drought stress triggers Ca 2+ signaling, reactive oxygen species (ROS), and abscisic acid (ABA) hormone-mediated signaling. Carotenoids act as signaling molecules, reducing oxidative damage and enabling plants to adapt to various stresses [15] . Carotenoids, as synthetic precursors of ABA, improve the drought resistance of cotton by regulating the production of ABA.…”