Application of Salicylic Acid Improves Filling of Inferior Grains of Rice during Late Maturity under Mild Cold Stress

Abstract

Medium‐ or late‐maturing varieties of rice (Oryza sativa L.) that are planted in agroecosystems in the middle and lower reaches of the Yangtze Valley of China always encounter cold stress during the late grain‐filling stage. Generally, grain yield and yield components are adversely affected under such circumstances. To alleviate these negative effects, salicylic acid (SA; i.e., SA0 [control, 0 mg L−1], SA100 [100 mg L−1], SA200 [200 mg L−1], SA300 [300 mg L−1], and SA400 [400 mg L−1]) was exogenously sprayed on plants of three rice cultivars at full heading in the field at the experimental base of China National Rice Research Institute (CNRRI) in Fuyang City, China (30°03′ N, 119°57′ E, 11 m asl). The results indicated that the mean grain‐filling rate and grain weight of the inferior grains were significantly increased under the SA200 (200 mg L−1) treatment and correspondingly contributed to a grain yield increase of 5.0 to 10.1% in comparison with the control. Further analysis showed that the SA200 treatment significantly increased the activity of the starch branching enzyme in inferior grains over the entire grain‐filling stage. Additionally, the photosynthetic rate, chlorophyll content, and soluble protein content of the flag leaf, which precisely reflected the senescence status, were significantly increased under the SA200 treatment, especially during late maturity under mild cold stress. We speculated that improved physiological changes during the late grain‐filling stage account for the increased grain weight and grain yield. Therefore, application of SA was a promising method of alleviating the adverse effects that were induced by mild cold stress on the grain yield of rice in the middle and lower reaches of the Yangtze Valley of China.

ATP Hydrolysis Determines Cold Tolerance by Regulating Available Energy for Glutathione Synthesis in Rice Seedling Plants

“…It plays an important role in Asian grain production, which has made a great contribution to food security (Aryal and Kandel 2017;Chauhan et al 2017;Rahaman and Shehab 2019). As a typical subtropical or tropical crop, rice plants are always damaged by cold sress (Zhao et al 2015;Wu et al 2016;Chen et al 2017). This stress is not only detrimental to plant growth and development (Su et al 2010;Thomashow 2010;Kim et al 2017), but also limits spatial distribution and grain productivity (Su et al 2010;Wang et al 2016;Uphoff and Thakur 2019).…”

Salicylic acid reverses pollen abortion of rice caused by heat stress

“…SA is known as a phenolic compound that naturally exists in plants at a very low concentration; however, it is a hormone-like substance that plays an important role for the regulation of plant growth and development [ 23 , 24 ]. Increasing evidence suggests that SA not only functions in response to biotic stress [ 25 , 26 ], but also plays an important role in abiotic stress, including cold [ 27 , 28 ], drought [ 29 ], heavy metal [ 23 , 30 ], and heat stress [ 3 , 31 , 32 ]. Khan et al [ 31 ] reported that exogenous acetyl SA enhanced the thermo-tolerance in four-week-old tomato seedlings by improving root morphological features and root activity.…”

A Rice Variety (BRRI dhan29) Yield Performance as Influenced by Foliar Application of Salicylic Acid in Bangladesh

“…Ibrahim, et al, (2014) showed 1000 grain weight increased due to the application of salicylic acid. Chen, et al (2017) also indicated that the mean grain-filling rate and grain weight of the inferior grains were significantly increased under the SA200 (200mgL -1 ).…”