Physiological and Transcriptomic Analyses Reveal the Mechanisms of Compensatory Growth Ability for Early Rice after Low Temperature and Weak Light Stress

Abstract

“Late spring coldness” (T) is a frequent meteorological disaster in the spring in southern China, often causing severe yield losses of direct-seeded early rice. In this study, we investigated the mechanisms underlying the differences in the compensatory growth ability of different rice genotypes by focusing on agronomic traits, physiological indicators, and transcriptome. The results showed that there were significant differences in the compensatory growth recovery ability of different genotypes after a combination of four days of low temperature and weak light stress. Only the strong compensatory growth genotype B116 was able to grow rapidly and reduce soluble protein and H2O2 concentrations rapidly after stress. By analyzing enzyme activity as well as endogenous hormone concentration, we found that the high superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities and high levels of abscisic acid (ABA) could reduce the damage of B116 during stress. Meanwhile, higher glutamine synthetase (GS) and nitrate reductase (NR) activity and higher levels of gibberellin A3(GA3), indoleacetic acid (IAA), and zeatin nucleoside (ZR) could enable B116 to grow rapidly after stress. The identified differentially expressed genes (DEGs) indicated that there were large differences in POD-related genes and gibberellin metabolism between B116 and B144 after stress; RT-PCR quantification also showed a trend consistent with RNA-seq, which may be an important reason for the differences in compensatory growth ability.

Multi-omics approach reveals the contribution of OsSEH1 to rice cold tolerance

“…Interestingly, we noticed that the soluble sugar content, ROS content, CAT activity and APX activity of WT were decreased after cold stress in this study. Further, we found similar results of soluble sugar content (Wang et al, 2022;Xu et al, 2023), ROS content (Wang et al, 2022;Shu et al, 2023) and antioxidative enzyme activity (Wang et al, 2022, Liu et al, Hao et al, 2022Liu et al, 2022) have been reported in previous studies. This results probably due to the impairment of the physiological metabolic sites of soluble sugar, ROS, CAT and APX by cold stress (Hao et al, 2022).…”

“…This results probably due to the impairment of the physiological metabolic sites of soluble sugar, ROS, CAT and APX by cold stress (Hao et al, 2022). In addition, the soluble sugar content, ROS content, CAT activity and APX activity of plants fluctuated under cold stress (Wang et al, 2022;Xu et al, 2023;Shu et al, 2023), rather than continuous increasing or decreasing, resulting in decreased content or activity of the physiological characteristics in a period of time after cold stress.…”

Physiological analysis reveals the mechanism of accelerated growth recovery for rice seedlings by nitrogen application after low temperature stress

“…It has been shown that the growth of rice seedlings is severely hindered when the average temperature is below 12°C ( Sipaseuth et al., 2007 ). In our previous study, we found that strong growth recovery rice variety had stronger antioxidant capacity, nitrogen metabolism capacity and higher levels of growth promoting hormones compared to weak growth recovery variety after low temperature and weak light stress ( Wang et al., 2022a ). It has been shown that the rapid growth recovery of rice seedlings after stress is also closely linked to their nitrogen utilization ( Liu et al., 2019 ).…”

“…In our previous experiments, we found significant differences in the growth recovery ability of different early rice varieties after low temperature and weak light stress when simulating “late spring coldness” weather. Accordingly, we conducted screening tests on 131 early rice varieties and investigated the mechanism of differences between strong and weak growth recovery materials ( Wang et al., 2022a ; Wang et al., 2023 ). In order to investigate the effects of supplemental nitrogen fertilization on the growth indexes, osmoregulatory substances, nitrogen accumulation, related enzyme activities, and endogenous hormones of rice after the stress, we chose two materials with clearly different growth recovery abilities after the stress and conducted a bucket experiment in an artificial climate chamber with different N concentration treatments.…”

Combined Analysis of Root Transcriptome, Metabolome and physiology on the mechanism of rapid growth recovery for rice seedlings after low temperature stress

“…In this study, after low temperature stress, the number of main roots, total root length, total root surface area, and total root volume of rice were signi cantly lower than the control, indicating signi cant inhibition of root growth, and the growth of above ground parts was also signi cantly weaker than the control. Previous studies have shown that the seedling height, leaf age, and fresh weight of the above ground parts are signi cantly lower than those of the control after low temperature stress [33], indicating that there is growth inhibition in both the above ground and underground parts after low temperature stress. It is worth noting that root length and seedling height are the most signi cant characteristics of our research, which is consistent with the research results of Hsu [37].…”