摘要
【目的】研究高温干旱胁迫后生长调节剂对棉花Bt蛋白含量的影响及其生理机制,为生产上抗虫棉的安全应用提供技术指导和理论依据。【方法】2021―2022年,以转基因抗虫棉常规品种泗抗1号(SK-1)和杂交品种泗抗3号(SK-3)为材料,于盛花期在人工气候室中设置高温(34℃和38℃)和干旱(田间最大持水量的50%和60%)胁迫处理,以32℃和田间最大持水量的75%为对照(CK)。胁迫7 d后,分别对棉株喷施清水(W)、200 mg·L^(-1)水杨酸(salicylic acid,SA)和20 mg·L^(-1)缩节胺(mepiquat chloride,DPC)。喷施处理后3 d,测定铃壳中谷氨酸草酰乙酸转氨酶(glutamic oxaloacetate transaminase,GOT)、谷氨酸丙酮酸转氨酶(glutamate pyruvate aminotransferase,GPT)、谷氨酰胺合成酶(glutamine synthetase,GS)、谷氨酸合成酶(glutamate synthase,GOGAT)、硝酸还原酶(nitrate reductase,NR)、肽酶和蛋白酶等氮代谢关键酶活性及可溶性蛋白含量和游离氨基酸含量。【结果】高温干旱胁迫会抑制供试品种铃壳中Bt蛋白的表达;SA和DPC处理可缓解该抑制效应,SA和DPC处理下Bt蛋白含量显著高于各胁迫条件下W处理,其SA处理下Bt蛋白含量增幅更大,但最终Bt蛋白含量仍低于未胁迫处理(CK)。2021年SA和DPC处理下SK-1的Bt蛋白含量较W处理分别提高51.3%~104.0%和22.0%~85.4%;2022年提高14.7%~91.1%和4.5%~67.8%。2021年SA和DPC处理下SK-3的Bt蛋白含量较W处理分别提高46.4%~98.3%和22.9%~60.4%,2022年分别提高18.8%~77.4%和14.6%~57.6%。品种间比较,SK-1对SA和DPC的响应更为显著,其Bt蛋白含量增幅高于SK-3。生理机制研究表明,SA和DPC处理显著提高了SK-1和SK-3的GPT、GOT、GOGAT和NR的活性和可溶性蛋白含量,显著降低了游离氨基酸含量和肽酶、蛋白酶活性。与W处理相比,2021年SA和DPC处理下SK-1的GOT活性提高70.3%~104.2%和36.7%~61.9%,GPT活性提高58.2%~231.2%和27.7%~88.9%,GS活性提高167.9%~197.3%和79.7%~139.4%,NR活性提高22.4%~53.6%和7.6%~42.8%,可溶性蛋白含量提高11.3%~40.6%和7.5%~20.3%,游离氨基酸含量降低15.6%~23.2%和6.3%~14.1%,蛋白酶活性降低5.5%~13.5%和2.7%~10.5%。2022年SK-1各指标的变化趋势与2021年趋势一致。2年试验中,SK-3表现与SK-1相似。总体上SA对以上指标的作用效果优于DPC。逐步回归分析表明,NR活性、氨基酸游离含量和GS活性是反映调节剂处理调控高温干旱胁迫后Bt棉铃壳杀虫蛋白含量高低的关键性指标。【结论】喷施SA和DPC能够提高蛋白合成相关酶活性,降低蛋白酶和肽酶活性和游离氨基酸含量,主要通过增强蛋白质合成能力从而提高高温干旱胁迫后Bt棉铃壳中Bt蛋白含量;SA效果更好;这为抗虫棉安全应用提供理论和实践指导。
[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.
作者
赵子胥
滕紫宁
王羽
陈媛
陈德华
张祥
Zhao Zixu;Teng Zining;Wang Yu;Chen Yuan;Chen Dehua;Zhang Xiang(Yangzhou University/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Co-Innovation Center for Modern Production Technology of Grain Crops,Yangzhou,Jiangsu 225009,China)
出处
《棉花学报》
北大核心
2025年第3期235-249,共15页
Cotton Science
基金
江苏省高等学校自然科学基金(22KJA210005)
国家自然科学基金(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)。
关键词
高温
干旱
BT棉
水杨酸
缩节胺
氮代谢
high temperature
drought
Bt cotton
salicylic acid
mepiquat chloride
nitrogen metabolism
作者简介
第一作者:赵子胥(2001-),男,硕士研究生,zzx1825960749@163.com;通信作者:张祥,zhangxiang@yzu.edn.cn。
