Kumari Archana, Goyal Meenakshi, Mittal Amandeep, Kumar Ravinder
Department of Biochemistry, Punjab Agricultural University, Ludhiana, 141004, India.
Department of Plant Breeding, and Genetics, Punjab Agricultural University, Ludhiana, 141004, India.
Protoplasma. 2022 May;259(3):809-822. doi: 10.1007/s00709-021-01703-4. Epub 2021 Sep 22.
Plants are equipped with a wide range of defensive mechanisms such as morphophysiological, biochemical, molecular, and hormonal signaling for protecting against insect-pest infestation. The infestation of a devastating pest shoot fly [Atherigona soccata (Rodani)] at seedling stage causes huge loss of sorghum crop productivity. In morphophysiological screening ICSV700, ICSV705, and IS18551 have been categorized as resistant, PSC-4 moderately resistant, SL-44 and SWARNA as susceptible. The present study focused on the role of defensive gene expression and its products viz: superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), polyphenol oxidase (PPO), phenyl alanine ammonia lyase (PAL), responsive enzymes, and metabolites restoring redox status in sorghum plants against shoot fly infestation. In both leaf and stem tissue of sorghum genotypes, shoot fly infestation induced SOD, APX, DHAR, GR, PAL, and PPO activities while CAT activity was significantly declined at 15 and 21 days after emergence (DAE). IS18551 with resistant behavior showed upregulation of SOD, GR, APX, and DHAR along with accumulation of ascorbate, glutathione enhancing redox status of the plant during shoot fly infestation at later stage of infestation. While SWARNA with susceptible response exhibited enhanced activity of phenylpropanoid pathway enzymes PAL and PPO which in turn increased the levels of secondary metabolites like o-dihydroxyphenol and other phenols deterring the insect to attack the plant. The qRT-PCR data predicted that stress-responsive genes were initially unregulated in SWARNA; however, at 21 DAE, multifold higher expression of SOD, CAT, APX, and PPO (24.8-, 37.2-, 21.7-, and 17.9-fold respectively) in 1S18551 indicates the resistance behavior of this genotype against insect infestation owing to sustainable development capability.
植物具备多种防御机制，如形态生理、生化、分子和激素信号传导等，以抵御虫害侵扰。毁灭性害虫高粱芒蝇[Atherigona soccata (Rodani)]在幼苗期的侵害会导致高粱作物生产力大幅损失。在形态生理筛选中，ICSV700、ICSV705和IS18551被归类为抗性品种，PSC - 4为中度抗性，SL - 44和SWARNA为敏感品种。本研究聚焦于防御基因表达及其产物的作用，即超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）、谷胱甘肽还原酶（GR）、多酚氧化酶（PPO）、苯丙氨酸解氨酶（PAL）等响应酶以及代谢物在高粱植株抵御芒蝇侵害过程中恢复氧化还原状态的作用。在高粱基因型的叶片和茎组织中，芒蝇侵害均诱导了SOD、APX、脱氢抗坏血酸还原酶（DHAR）、GR、PAL和PPO的活性，而CAT活性在出苗后15天和21天显著下降。具有抗性表现的IS18551在侵害后期表现出SOD、GR、APX和DHAR的上调以及抗坏血酸、谷胱甘肽的积累，增强了植株的氧化还原状态。而表现出敏感反应的SWARNA则表现出苯丙烷途径酶PAL和PPO的活性增强，进而增加了邻二羟基酚和其他酚类等次生代谢物的水平，阻止昆虫攻击植株。qRT - PCR数据预测，应激响应基因在SWARNA中最初未被上调；然而，在出苗后21天，1S18551中SOD、CAT、APX和PPO的表达量分别提高了24.8倍、37.2倍、21.7倍和17.9倍，这表明该基因型由于具有可持续发展能力而对昆虫侵害具有抗性。
