Effects of water stress on starch synthesis and accumulation of two rice cultivars at different growth stages

Guangyi Chen; Ligong Peng; Jing Gong; Jin Wang; Chaoyue Wu; Xiaodong Sui; Yunfeng Tian; Mingming Hu; Congmei Li; Xingmei He; Hong Yang; Qiuqiu Zhang; Yuyuan Ouyang; Yan Lan; Tian Li

doi:10.3389/fpls.2023.1133524

Effects of water stress on starch synthesis and accumulation of two rice cultivars at different growth stages

Front Plant Sci. 2023 Apr 25:14:1133524. doi: 10.3389/fpls.2023.1133524. eCollection 2023.

Authors

Guangyi Chen¹, Ligong Peng², Jing Gong¹, Jin Wang¹, Chaoyue Wu¹, Xiaodong Sui¹, Yunfeng Tian³, Mingming Hu¹, Congmei Li¹, Xingmei He¹, Hong Yang¹, Qiuqiu Zhang¹, Yuyuan Ouyang⁴, Yan Lan⁵, Tian Li¹

Affiliations

¹ College of Agronomy, Sichuan Agricultural University, Chengdu, China.
² College of Agronomy, South China Agricultural University, Guangzhou, China.
³ Rice Research Institute, Sichuan Agricultural University, Chengdu, China.
⁴ Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China.
⁵ College of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China.

Abstract

Rice is a water intensive crop and soil water conditions affect rice yield and quality. However, there is limited research on the starch synthesis and accumulation of rice under different soil water conditions at different growth stages. Thus, a pot experiment was conducted to explore the effects of IR72 (indica) and Nanjing (NJ) 9108 (japonica) rice cultivars under flood-irrigated treatment (CK, 0 kPa), light water stress treatment (L, -20 ± 5 kPa), moderate water stress treatment (M, -40 ± 5 kPa) and severe water stress treatment (S, -60 ± 5 kPa) on the starch synthesis and accumulation and rice yield at booting stage (T1), flowering stage (T2) and filling stage (T3), respectively. Under LT treatment, the total soluble sugar and sucrose contents of both cultivars decreased while the amylose and total starch contents increased. Starch synthesis-related enzyme activities and their peak activities at mid-late growth stage increased as well. However, applying MT and ST treatments produced the opposite effects. The 1000-grain weight of both cultivars increased under LT treatment while the seed setting rate increased only under LT3 treatment. Compared with CK, water stress at booting stage decreased grain yield. The principal component analysis (PCA) showed that LT3 got the highest comprehensive score while ST1 got lowest for both cultivars. Furthermore, the comprehensive score of both cultivars under the same water stress treatment followed the trend of T3 > T2 > T1, and NJ 9108 had a better drought-resistant ability than IR72. Compared with CK, the grain yield under LT3 increased by 11.59% for IR72 and 16.01% for NJ 9108, respectively. Overall, these results suggested that light water stress at filling stage could be an effective method to enhance starch synthesis-related enzyme activities, promote starch synthesis and accumulation and increase grain yield.

Keywords: enzyme activity; rice; starch synthesis; water stress; yield.

Grants and funding

This work was supported by funds from the Guizhou Provincial Science and Technology Foundation (QKHJC[2020]1Z020) and the Project of Science and Technology of Chengdu City (2022YFH0029 and 2022-YF09-00036-SN).