昆虫学报 ›› 2022, Vol. 65 ›› Issue (12): 1668-1677.doi: 10.16380/j.kcxb.2022.12.012

• 研究论文 • 上一篇    下一篇

苦瓜素Ⅰ对斜纹夜蛾几丁质酶基因(SlCht)和几丁质合成酶基因(SlCHS-A)表达及其生长发育的影响

张展滔, 林晓菊, 辜晓婷, 叶凯翔, 张伟钊, 金丰良, 许小霞*   

  1. (华南农业大学植物保护学院, 广东省生物农药创制与应用重点实验室, 广州 510642)
  • 出版日期:2022-12-20 发布日期:2023-01-19

Effects of momordicin I on the expression of chitinase gene (SlCht) and chitinase synthase gene (SlCHS-A) in Spodoptera litura (Lepidoptera: Noctuidae) and its growth and development

ZHANG Zhan-Tao, LIN Xiao-Ju, GU Xiao-Ting, YE Kai-Xiang, ZHANG Wei-Zhao, JIN Feng-Liang, XU Xiao-Xia*   

  1.  (Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China)
  • Online:2022-12-20 Published:2023-01-19

摘要: 【目的】几丁质酶和几丁质合成酶对昆虫的变态发育极其重要。本研究旨在阐明苦瓜素Ⅰ对斜纹夜蛾Spodoptera litura几丁质酶和几丁质合成酶基因表达及其生长发育的影响。【方法】利用RT-qPCR检测斜纹夜蛾几丁质酶基因(SlCht)和几丁质合成酶基因(SlCHS-A)在斜纹夜蛾不同发育阶段(卵、幼虫、预蛹、蛹和成虫)和4-6龄幼虫不同组织(体壁、中肠、脂肪体、血细胞、头部和马氏管)中的表达水平以及注射苦瓜素Ⅰ溶液(4 μg/头) 24, 48和72 h时斜纹夜蛾SlCht和SlCHS-A在6龄幼虫各组织中的表达水平。分析在斜纹夜蛾4龄幼虫中注射不同浓度(31.25, 62.5, 125, 250和500 ng/头)的苦瓜素Ⅰ溶液对幼虫和蛹历期、幼虫增重、蛹重、蛹长度、化蛹率、羽化率和存活率的影响,并利用体视显微镜观察斜纹夜蛾幼虫的表型变化。【结果】SlChtSlCHS-A在斜纹夜蛾中的表达具有发育阶段特异性。SlChtSlCHS-A在卵期表达量最高,幼虫期和预蛹期的表达量较低;在各幼虫期又表现为6龄幼虫期表达量最高,在其他龄期的表达量低。SlChtSlCHS-A在斜纹夜蛾6龄幼虫中也显示出组织特异性表达,在血细胞和体壁中高表达,在头部、中肠和脂肪体中低表达。在斜纹夜蛾6龄幼虫中注射苦瓜素Ⅰ能诱导SlChtSlCHS-A在其各组织中表达量降低;在4龄幼虫中注射苦瓜素Ⅰ后,斜纹夜蛾的生长发育受到抑制,幼虫增重延缓,发育历期延长,化蛹率下降甚至化蛹失败,幼虫及蛹出现较高的畸形率。【结论】苦瓜素Ⅰ可通过诱导SlChtSlCHS-A表达量的降低来实现对斜纹夜蛾生长发育的抑制作用。本研究为进一步阐明苦瓜素对斜纹夜蛾生长发育的抑制机制提供了新的理论基础,并为进一步应用苦瓜素Ⅰ进行防控奠定了基础。

关键词: 斜纹夜蛾; 苦瓜素Ⅰ; 几丁质酶; 几丁质合成酶; 基因表达, 生长发育

Abstract: 【Aim】 Chitinase and chitin synthetase are of great importance to the metamorphosis in insects. This study aims to elucidate the effects of momordicin I on the expression of chitinase and chitin synthase genes in Spodoptera litura and its growth and development. 【Methods】 The expression levels of chitinase gene (SlCht) and chitinase synthase gene (SlCHS-A) in different developmental stages (egg, larva, prepupa, pupa and adult) and tissues (integument, midgut, fat body, hemocyte, head and Malpighian tubules) of the 4th-6th instar larvae of S. litura, and in various tissues of the 6th instar larvae at 24, 48 and 72 h after injection with momordicin I solution (4 μg/individual) were detected by RT-qPCR. The effects of injection of momordicin I at different concentrations (31.25, 62.5, 125, 250 and 500 ng/individual) into the 4th instar larvae of S. litura on the larval and pupal duration, larval weight gain, pupal weight, pupal length, pupation rate, emergence rate and survival rate were analyzed, and the phenotypic changes of S. litura larvae were also observed under stereoscopic microscope. 【Results】 SlCht and SlCHS-A showed developmental stagespecific expression in S. litura, both with the highest expression levels in the egg stage but significantly lower expression levels in the larval and prepupal stages, and with the highest expression level in the 6th larval instar during the larval stage. SlCht and SlCHS-A also exhibited tissue-specific expression in the 6th instar larvae of S. litura, both being highly expressed in hemocyte and integument, and lowly expressed in head, midgut and fat body. Injection of momordicin I into the 6th instar larvae of S. litura induced the decreased expression of SlCht and SlCHS-A genes in their various tissues. After injection of momordicin I into the 4th instar larvae of S. litura, the growth and development of S. litura were inhibited, the larval weight gain was delayed, the developmental duration was prolonged, the pupation rate was decreased and even failure to pupate was observed, and high malformation rates of larvae and pupae were found. 【Conclusion】 Momordicin I can inhibit the growth and development of S. litura by inducing the decreased expression of SlCht and SlCHS-A. This study provides a new theoretical basis for further elucidation of the inhibitory mechanism of momordicin on the growth and development of S. litura, and lays a foundation for the application of momordicin I in the prevention and control of this insect pest.

Key words: Spodoptera litura, momordicin I, chitinase, chitin synthase, gene expression, growth and development