DU H Y, Liu H L, Liu D X, Liu H P, Kurtenbach R
College of Life Science and Agronomy/Henan Key Laboratory of Crop Molecular Breeding and Bioreactor, Zhoukou Normal University, Zhoukou 466001, Henan, China.
J Biosci. 2022;47.
Deoxyribonucleic acid-protein (DNAP) of the cell nucleus was purified from developing wheat () embryo cells under drought stress, with two cultivars differing in drought tolerance as experimental materials - Longmai No. 079 (drought-tolerant) and Wanmai No. 52 (drought-sensitive). Levels of polyamines (PAs) non-covalently conjugated to the DNA and covalently conjugated to the proteins of DNAP were detected. After soil drought treatment for 10 days, in drought-tolerant Longmai No. 079, the increases in the levels of spermine and spermidine non-covalently conjugated to DNA of DNAP were more statistically significant (P<0.05) than in drought-sensitive Wanmai No. 52. Treatment of Wanmai No. 52 with exogenous Spm could not only enhance the tolerance of the cultivar to drought stress, as judged by flag leaf water content, plasma membrane permeability and grain growth, but also elevate the levels of spermine and spermidine noncovalently conjugated to the DNA of the cultivar. On the contrary, treatment of Longmai No. 079 with methylglyoxyl-bis guanylhydrazone, an inhibitor of S-adenosylmethionine decarboxylase, could significantly (P<0.05) aggravate the drought stress to this cultivar, accompanied by a marked decreases in the levels of spermine and spermidine non-covalently conjugated to the DNA of the cultivar. On the other hand, the content of putrescine covalently conjugated to the proteins of DNAP rose more markedly (P<0.05) in Longmai No. 079 than in Wanmai No. 52. The transglutaminase inhibitor, -phenanthrolin, could markedly reduce the drought-induced increase in the level of putrescine covalently conjugated to the proteins of DNAP and aggravate drought stress to the two cultivars. Collectively, it could be inferred that spermine and spermidine non-covalently conjugated to the DNA and putrescine covalently conjugated to the proteins of DNAP in the developing grain embryo cell nucleus might enhance the tolerance of wheat plants to soil drought.
以两个耐旱性不同的小麦品种——龙麦079（耐旱型）和皖麦52（干旱敏感型）为试验材料，从干旱胁迫下发育中的小麦胚细胞中纯化细胞核脱氧核糖核酸 - 蛋白质（DNAP）。检测了与DNA非共价结合以及与DNAP蛋白质共价结合的多胺（PAs）水平。土壤干旱处理10天后，在耐旱的龙麦079中，与DNAP的DNA非共价结合的精胺和亚精胺水平的增加在统计学上比干旱敏感的皖麦52更显著（P<0.05）。用外源Spm处理皖麦52，从旗叶含水量、质膜透性和籽粒生长判断，不仅能提高该品种对干旱胁迫的耐受性，还能提高与该品种DNA非共价结合的精胺和亚精胺水平。相反，用S - 腺苷甲硫氨酸脱羧酶抑制剂甲基乙二醛 - 双脒腙处理龙麦079，能显著（P<0.05）加重该品种的干旱胁迫，同时与该品种DNA非共价结合的精胺和亚精胺水平显著降低。另一方面，与DNAP蛋白质共价结合的腐胺含量在龙麦079中比在皖麦52中上升更明显（P<0.05）。转谷氨酰胺酶抑制剂邻菲罗啉能显著降低干旱诱导的与DNAP蛋白质共价结合的腐胺水平的增加，并加重两个品种的干旱胁迫。总体而言，可以推断，发育中的籽粒胚细胞核中与DNA非共价结合的精胺和亚精胺以及与DNAP蛋白质共价结合的腐胺可能增强小麦植株对土壤干旱的耐受性。
