棉花学报2025，Vol.37Issue(3)：235-249,15.DOI:10.11963/cs20240048
高温干旱胁迫后调节剂对棉花铃壳中Bt蛋白含量及氮代谢的影响
Effects of exogenous growth regulators on Bt protein content and nitrogen metabolism in cotton boll shell under high temperature and drought stress
摘要
Abstract
[Objective]In order to provide technical guidance and a theoretical basis for the safe application of insect-resistant cotton in production,the effect of exogenous growth regulator on insecticidal protein content of Bt cotton and its underlying physiological mechanism under high temperature and drought stress were studied.[Methods]The transgenic insect-resistant cotton cultivar Sikang 1(SK-1)and hybrid cultivar Sikang 3(SK-3)were used as experimental materials,the daily temperature of 32℃and 75%field capacity were used as control,and the artificial climate chamber was subjected to different high temperature levels(34℃and 38℃)and drought stress(50%and 60%field capacity)during the peak flowering period in 2021-2022.After 7 days of stress,cotton plants were sprayed with water(W),200 mg·L-1 salicylic acid(SA),and 20 mg·L-1 mepiquat chloride(DPC),respectively.Three days later,the boll shells were sampled to determine the activities of glutamic oxaloacetate transaminase(GOT),glutamate pyruvate aminotransferase(GPT),glutamine synthetase(GS),glutamate synthase(GOGAT),nitrate reductase(NR),protease and other key enzymes of nitrogen metabolism,as well as soluble protein and free amino acid content.[Results]High temperature and drought stress inhibit the content of Bt protein in the boll shells of two tested varieties,while treatments with SA and DPC can alleviate this inhibitory effect.The Bt protein content under SA or DPC treatments is significantly higher than that of W treatment under various stress conditions,with the increase in SA treatment being more pronounced.The Bt protein content remains lower than that under the non-stressed control.In 2021,the Bt protein content in SK-1 treated with SA and DPC after heat and drought stresses increased by 51.3%-104.0%and 22.0%-85.4%,respectively,compared with the W treatment.In 2022,the increase was 14.7%-91.1%and 4.5%-67.8%.In SK-3,the Bt protein content in 2021 increased by 46.4%-98.3%and 22.9%-60.4%under SA and DPC treatments after heat and drought stresses,respectively,compared with the W treatment.In 2022,the increase was 18.8%-77.4%and 14.6%-57.6%,respectively.Among the varieties,SK-1 showed a more significant response to SA and DPC,with a higher increase in Bt protein content than that of SK-3.Physiological mechanism studies showed that SA and DPC treatments after heat and drought stresses significantly increased the activities of GPT,GOT,GOGAT,and NR,as well as the soluble protein content in SK-1 and SK-3.They also significantly reduced the free amino acid content,peptidase,and protease activities.Compared with the W treatment in 2021,SA and DPC treatments increased GOT activity in SK-1 by 70.3%-104.2%and 36.7%-61.9%,GPT activity by 58.2%-231.2%and 27.7%-88.9%,GS activity by 167.9%-197.3%and 79.7%-139.4%,NR activity by 22.4%-53.6%and 7.6%-42.8%,soluble protein content by 11.3%-40.6%and 7.5%-20.3%,while free amino acid content decreased by 15.6%-23.2%and 6.3%-14.1%,and protease activity decreased by 5.5%-13.5%and 2.7%-10.5%,respectively.The trend of changes in the indicators of SK-1 in 2022 was consistent with that in 2021.In the two-year experiment,SK-3 showed similar performance to SK-1.Overall,the effects of SA on the above indicators were superior to those of DPC.Stepwise regression analysis further indicated that NR activity,free amino acid content and GS activity was a key index to reflect the content of insecticidal protein in Bt cotton boll shell after growth regulator treatment under high temperature and drought stress.[Conclusion]Spraying SA and DPC can enhance the activity of enzymes related to protein synthesis,reduce the activity of proteases and peptidases,and decrease the content of free amino acids.The primary mechanism is to enhance the capacity of protein synthesis,thereby increasing the Bt protein content in the boll shell of Bt cotton after high temperature and drought stress.Additionally,the effect of SA was better than DPC.This provides theoretical and practical guidance for the safe application of insect-resistant cotton.关键词
高温/干旱/Bt棉/水杨酸/缩节胺/氮代谢Key words
high temperature/drought/Bt cotton/salicylic acid/mepiquat chloride/nitrogen metabolism引用本文复制引用
赵子胥,滕紫宁,王羽,陈媛,陈德华,张祥..高温干旱胁迫后调节剂对棉花铃壳中Bt蛋白含量及氮代谢的影响[J].棉花学报,2025,37(3):235-249,15.基金项目
江苏省高等学校自然科学基金(22KJA210005) （22KJA210005）
国家自然科学基金(31901462) （31901462）
江苏省高校优势学科建设工程 （）
江苏高校品牌专业建设工程(PPZY2015A060) （PPZY2015A060）
