Department of Plant Pathology, University of Agricultural Sciences, Bangalore, India.
Department of Genetics and Plant Breeding, College of Agriculture, V. C. Farm, Mandya, India.
Sci Rep. 2022 Apr 9;12(1):5993. doi: 10.1038/s41598-022-10010-8.
Red seaweed-derived biostimulants facilitate plant health and impart protection against abiotic stress conditions by their bioactive compounds and plant nutrients. The potency of red seaweed biostimulants (LBS6 and LBD1) on rice cv. IR-64 in response to fungicides induced stress was investigated in this study. Foliar application of LBS6 maintained the stomatal opening and leaf temperature under the fungicidal stress condition. Reactive Oxygen Species (ROS) such as hydrogen peroxide and superoxide radicals were significantly reduced in LBS6-treated stressed plants. After applying seaweed biostimulants, ROS production was stabilized by antioxidants viz., CAT, APX, SOD, POD, and GR. LBS-6 application increased the Ca and K levels in the stressed plants, which perhaps interacted with ROS and stomatal opening signalling systems, respectively. In the rice plants, fungicidal stress elevated the expression of stress-responsive transcriptional factors (E2F, HSFA2A, HSFB2B, HSFB4C, HSFC1A, and ZIP12). A decline in the transcript levels of stress-responsive genes was recorded in seaweed treated plants. For the first time, we present an integrative investigation of physicochemical and molecular components to describe the mechanism by which seaweed biostimulants in rice improve plant health under fungicidal stress conditions.
红海藻源生物刺激素通过其生物活性化合物和植物营养物质促进植物健康，并赋予植物对非生物胁迫条件的保护。本研究探讨了红海藻生物刺激素（LBS6 和 LBD1）对水稻品种 IR-64 对杀菌剂诱导胁迫的反应。叶面喷施 LBS6 在杀菌剂胁迫条件下保持气孔开度和叶片温度。活性氧（ROS）如过氧化氢和超氧自由基在 LBS6 处理的胁迫植物中显著减少。在施用海藻生物刺激素后，抗氧化剂 CAT、APX、SOD、POD 和 GR 稳定了 ROS 的产生。LBS-6 的应用增加了胁迫植物中的 Ca 和 K 水平，这可能分别与 ROS 和气孔开放信号系统相互作用。在水稻植株中，杀菌剂胁迫会提高应激反应转录因子（E2F、HSFA2A、HSFB2B、HSFB4C、HSFC1A 和 ZIP12）的表达。在经过海藻处理的植物中，应激反应基因的转录水平下降。我们首次对物理化学和分子成分进行综合研究，以描述海藻生物刺激素在水稻中提高植物在杀菌剂胁迫条件下健康状况的机制。
