Functional Analysis of OsCIPK17 in Rice Grain Filling

Abstract

We used mutant cipk17 and Nipponbare in field experiments to analyze agronomic traits, photosynthetic parameters, transcriptome, and gene expression. The results demonstrated cytoplasmic localization of OsCIPK17, while GUS allogeneic (A. thaliana) tissue-staining and quantitative analysis showed the gene was expressed in many organs, including flower buds; furthermore, it was involved in root, stem, and leaf growth. Compared to Nipponbare plants, grain filling rate and final grain weight decreased in plants of the knockout mutant owing to a delay in attainment of maximum grain filling rate. Photosystem II (PSII) efficiency was also reduced. Enrichment analysis showed that the functions of differentially expressed genes (DEGs) focused on nucleoside-, nucleotide-, and lipid-binding, as well as hydrolase, transferase, and phosphorylase activities. Signaling pathways mainly included starch and sucrose metabolism, as well as photosynthesis. Additionally, some DEGs were verified by fluorescence analysis. The results showed that knockout of OsCIPK17 affected photosynthesis and starch-, sucrose-, and amino acid metabolism-related gene expression; furthermore, the mutation reduced PSII utilization efficiency, it blocked the synthesis and metabolism of starch and sucrose, and affected the formation and transport of assimilates, thereby reducing final grain weight.

The OsCBL8–OsCIPK17 Module Regulates Seedling Growth and Confers Resistance to Heat and Drought in Rice

“…As shown in Supplementary Figure S12G–I , pods in progressively late developmental stages showed gradually lighter blue staining. The GUS tissue staining results in transgenic Arabidopsis thaliana with the OsCBL8 promoter region were similar to those in the transgenic Arabidopsis with the OsCIPK17 promoter region, as reported in previous studies [ 26 ]. We also stained Gus tissue of 10-day-old Arabidopsis thaliana transformed with OsCBL8 and OsCIPK17 promoter regions after high temperature treatment.…”

“…Transgenic Arabidopsis thaliana with promoters of the OsCBL8 , maintained in this study, was produced following the methods described above [ 26 ]. β-Glucuronidase (GUS) staining was performed in tissues of T2 transgenic Arabidopsis thaliana containing the GUS reporter gene using a kit (Tiangen, Beijing, China).…”

Combined metabolomic and transcriptomic analysis reveals key components of OsCIPK17 overexpression improves drought tolerance in rice

“…Presumably, OsCBL8 senses the Ca 2+ signal upon exposure to drought and activate OsCIPK17 to respond to stress (Gao et al, 2022a). Our previous research also shows that OsCIPK17 also plays an important role in the rice filling process (Gao et al, 2022b). In the present study, OsCIPK17-OE exhibited drought tolerance through additional root growth under stress (Figure 1D).…”