DOI: doi.org/10.1016/j.plaphy.2024.108379

发表期刊：Plant Physiology and Biochemistry

链接：https://doi.org/10.1016/j.plaphy.2024.108379作者：Bizhen Cheng , Muhammad Jawad Hassan , Dandan Peng , Ting Huang , Yan Peng **, Zhou Li *

Abstract

White clover is widely cultivated as a leguminous forage or ground cover plant worldwide. However, soil salinization decreases its yield and quality. Aims of the present experiment were to elucidate the impact of seed pretreatment with spermidine (Spd) or spermine (Spm) on amylolysis, Na⁺/K⁺accumulation, and metabolic homeostasis during germination. Seed was soaked in distilled water (control), Spd or Spm solution and then germinated under optimal or salt stress conditions for 7 days. Results showed that germination vigor, germination percentage, or seed vigour index of seeds pretreatment with Spd increased by 7%, 11%, or 70% when compared with water-pretreated seeds under salt stress, respectively. Germination percentage or seed vigour index of seeds pretreatment with Spm increased by 17% or 78% than water-pretreated seeds under saline condition, respectively. In response to salt stress, accelerated amylolysis via activation of β-amylase activity was induced by Spd or Spm pretreatment. Spd or Spm pretreatment also significantly enhanced accumulation of diverse amino acids, organic acids, sugars, and other metabolites (putrescine, myo-inositol, sorbitol, daidzein etc.) associated with enhanced osmotic adjustment, antioxidant capacity, and energy supply during germination under salt stress. In addition, Spd or Spm pretreatment not only significantly reduced salt-induced K⁺loss and overaccumulation of Na⁺, but also improved the ratio of K⁺to Na⁺, contributing to Na⁺and K⁺balance in seedlings. In response to salt stress, seeds pretreatment with Spd or Spm up-regulated transcription level ofNHX2related to enhancement in compartmentation of Na⁺from cytoplasm to vacuole, thus reducing Na⁺toxicity in

cytoplasm. Spm priming also uniquely up-regulated transcription levels ofSKOR,HKT1, andHAL2associated with K⁺and Na⁺homeostasis and decline in cytotoxicity under salt stress.

Keywords

Starch metabolism,Metabolome,Organic metabolites,Gene expression,Ionic equilibrium,Salinity