Crop Improvement Group, International Centre for Genetic Engineering, and Biotechnology, New Delhi 110067, India.
Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.
Pestic Biochem Physiol. 2022 Mar;182:105026. doi: 10.1016/j.pestbp.2021.105026. Epub 2021 Dec 28.
In rice farming, the blast disease caused by Magnaporthe oryzae (T.T. Hebert) M.E. Barr. is one of the primary production constraints worldwide. The current blast management options such as blast-resistant varieties and spraying fungicides are neither durable nor commercially and environmentally compatible. In the present study, we investigated the antifungal and defense elicitor activity of potassium phosphite (Phi) against M. oryzae on elite rice cultivar BPT5204 (popularly known as Samba Mahsuri in India) and its transgenic rice variant (ptxD-OE) over-expressing a phosphite dehydrogenase enzyme. The Phi was evaluated both preventively and curatively on rice genotypes where the preventive spray of Phi outperformed the Phi curative application with significant reductions in both rice blast severity (35.67-60.49%) and incidence (22.27-53.25%). Moreover, the application of Phi increased the levels of photosynthetic pigments (Chlorophyll and Carotenoids) coupled with increased activity of defense enzymes (PAL, SOD, and APx). Besides, Phi application also induced the expression of defense-associated genes (OsCEBiP and OsPDF2.2) in the rice leaf. Furthermore, the Phi application reduced the reactive Malondialdehyde (lipid peroxidation) to minimize the cellular damage incited by Magnaporthe in rice. Overall, the present study showed the potential of Phi for blast suppression on rice as an alternative to the current excessive use of toxic fungicides.
在水稻种植中，由稻瘟病菌（Magnaporthe oryzae）引起的稻瘟病是全球主要的生产制约因素之一。目前的稻瘟病管理措施，如抗稻瘟病品种和喷洒杀菌剂，既不持久，也不具有商业和环境兼容性。在本研究中，我们研究了亚磷酸钾（Phi）对精英水稻品种 BPT5204（在印度俗称 Samba Mahsuri）及其过表达亚磷酸脱氢酶的转基因水稻变体（ptxD-OE）的抗真菌和防御激发活性。我们评估了 Phi 的预防和治疗效果，结果表明，预防喷洒 Phi 比 Phi 治疗应用效果更好，可显著降低稻瘟病的严重程度（35.67-60.49%）和发生率（22.27-53.25%）。此外，Phi 的应用增加了光合作用色素（叶绿素和类胡萝卜素）的水平，并提高了防御酶（PAL、SOD 和 APx）的活性。此外，Phi 的应用还诱导了水稻叶片中防御相关基因（OsCEBiP 和 OsPDF2.2）的表达。此外，Phi 的应用减少了活性丙二醛（脂质过氧化）的产生，以最大程度地减少稻瘟病菌在水稻中引起的细胞损伤。总的来说，本研究表明，Phi 作为目前过度使用有毒杀菌剂的替代物，具有在水稻上抑制稻瘟病的潜力。
