中国农业科学 ›› 2022, Vol. 55 ›› Issue (23): 4614-4625.doi: 10.3864/j.issn.0578-1752.2022.23.004

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

昼夜变温下高温与干旱胁迫对Bt棉毒蛋白含量的影响及其生理机制

尹彦雨(),邢雨桐,吴天凡,王李妍,赵子胥,胡天然,陈源,陈媛,陈德华*(),张祥*()   

  1. 扬州大学/江苏省作物遗传生理国家重点实验室培育点,江苏扬州 225009
  • 收稿日期:2022-01-04 接受日期:2022-04-19 出版日期:2022-12-01 发布日期:2022-12-06
  • 联系方式: 尹彦雨,E-mail:2026231662@qq.com。
  • 基金资助:
    江苏省高等学校自然科学研究(22KJA210005);国家自然科学基金(31901462);扬州大学大学生科创基金(X20210630);扬州大学大学生科创基金(X20210607);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)

Cry1Ac Protein Content Responses to Alternating High Temperature Regime and Drought and Its Physiological Mechanism in Bt Cotton

YIN YanYu(),XING YuTong,WU TianFan,WANG LiYan,ZHAO ZiXu,HU TianRan,CHEN Yuan,CHEN Yuan,CHEN DeHua*(),ZHANG Xiang*()   

  1. Yangzhou University/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou 225009, Jiangsu
  • Received:2022-01-04 Accepted:2022-04-19 Published:2022-12-01 Online:2022-12-06

摘要: 目的 明确Bt棉叶片Cry1Ac毒蛋白含量对昼夜变温下高温干旱胁迫响应及其生理机制,为生产中Bt棉抗虫性的安全稳定利用提供参考。方法 2019—2020年在扬州大学农学院,以常规种泗抗1号(SK-1)和杂交种泗抗3号(SK-3)为材料,以温度和土壤水分含量为因子,温度分别设为34℃(白天,7:00—19:00)/28℃(夜间,19:00—7:00)(A1)、38℃/28℃(A2);土壤水分含量分别为田间土壤最大持水量的50%(B1)和60%(B2),并以32℃/28℃、田间土壤最大持水量的75%为对照(CK)。各处理分别持续4、7、10 d(DAS)。结果 不同处理导致叶片中Cry1Ac毒蛋白含量降低,且随着胁迫时间的延长,下降幅度增加。处理间相比,A1B2处理下降幅度最少,7 DAS后开始显著低于CK;A1B1处理下降幅度其次,4 DAS后显著低于CK;A2B1、A2B2处理在4 DAS显著下降。可溶性蛋白(SP)含量、硝酸还原酶(NR)、谷氨酸丙酮酸转氨酶(GPT)、谷氨酸草酰乙酸转氨酶(GOT)、谷氨酰胺合成酶(GS)、游离氨基酸(aa)和谷氨酸合成酶(GOGAT)等活性变化趋势与毒蛋白一致,且呈极显著正相关,而Bt基因表达量、单宁含量、蛋白酶、肽酶活性则呈上升趋势。逐步回归和通径分析筛选出NR、GPT、GS等3个关键指标可反映Bt棉Cry1Ac毒蛋白含量高低,且三者对Cry1Ac毒蛋白含量有较大的正效应。结论 昼夜变温下高温和干旱互作导致Bt棉Cry1Ac毒蛋白含量降低,且随持续期延长下降幅度逐渐增大。其中34℃/28℃和田间土壤最大持水量60%胁迫7—10 d内与对照无显著差异。但与昼夜持续高温相比,昼夜变温的高温胁迫下Cry1Ac毒蛋白含量下降幅度减小和时期明显推迟。NR、GPT、GS是决定Cry1Ac毒蛋白含量高低的关键指标。

关键词: Bt棉, Cry1Ac毒蛋白, 高温, 干旱, 生理机制

Abstract:

【Objective】 This study was conducted to investigate the effects of alternating high temperature and drought on the content of Cry1Ac protein in Bt cotton and the underlying physiological mechanism, so as to provide a reference for the safe and stable utilization of insect resistance of Bt cotton in production.【Method】 The conventional cultivar Sikang 1 (SK-1) and hybrid cultivar Sikang 3 (SK-3) were used in 2019 and 2020 in experimentally controlled greenhouse, Yangzhou University. From 7:00 am to 7:00 pm, two high-temperature treatments [34℃ (A1) and 38℃ (A2)] were imposed on cotton plants, followed by an optimum temperature 28℃ during the remaining night hours. There were two treatments for soil moisture content, which were 50% (B1) and 60% (B2) field capacity. The treatment with 32℃/28℃ and 75% field capacity was set as the control (CK). The leaf Cry1Ac protein content and its physiological mechanism were detected on 4, 7, and 10 days after stress (DAS), respectively.【Result】 Compared with CK, the Cry1Ac protein content all decreased under the stresses of high temperature and drought, and with the extension of the stress time, greater decrease was observed. The extent of decline for A1B2 was the smallest, followed by A1B1, while A2B1 and A2B1 were the largest. The Cry1Ac protein content under A1B2 was significantly lower than CK after 7 DAS, while the significant differences between A1B1, A2B2, A2B2 and CK were detected after 4 DAS. The Bt gene expression level, soluble protein (SP), free amino acid (aa) contents, nitrate reductase (NR), the glutamic pyruvic transaminase (GPT), glutamic oxaloacetate transaminase (GOT), glutamine synthetase (GS) and glutamate synthase (GOGAT) activities showed a downward trend. While the tannin content, the activities of protease and peptidase showed an upward trend. The correlation analysis and path analysis showed SP, aa, NR, GPT, GOT, GS, and GOGAT were positively correlated with Cry1Ac protein content. The tannin content, activities of protease, and peptidase were negatively correlated with Cry1Ac protein content. NR, GPT and GS could be key indices for the Cry1Ac protein content.【Conclusion】 The interaction of high temperature and drought resulted in the decrease of Cry1Ac protein content in Bt cotton, with greater decrease observed as the stress extended. There was no significant difference between the treatment with 34℃/28℃ and 60% field capacity and CK in 7-10 DAS. The reduction extent of Cry1Ac for alternating high temperature regime and drought decreased and the period was delayed. NR, GPT and GS could be key indices for the Cry1Ac protein content.

Key words: Bt cotton, Cry1Ac protein, high temperature, drought, physiological mechanism