Regulation of gene expression involved in the remobilization of rice straw carbon reserves results from moderate soil drying during grain filling

Abstract

Carbon reserves in rice straw before flowering contribute greatly to grain filling. Moderate soil drying imposed at the post-anthesis stage significantly promotes carbon reserve remobilization in straws of rice, but the regulation of this process at the proteomic and transcriptomic level remains poorly understood. In this study, we applied moderate soil drying (MD) to rice at the post-anthesis stage, which was followed by dynamic proteomic and transcriptomic studies using SWATH-MS and RNA-seq analysis. MD treatment upregulated the proteins alpha-glucosidase, beta-glucosidase and starch phosphorylase, which are responsible for starch degradation. Furthermore, MD treatment enhanced the expression of proteins involved in the sucrose synthesis pathway, including SPS8 and SPP1. In addition, various monosaccharide transporters (MSTs) and sucrose transporter 2 (SUT2), which are pivotal in carbon reserve remobilization, were also upregulated in straw by MD treatment. Differentially expressed transcription factors, including GRAS, TCP, trihelix, TALE, C3H, and NF-YC, were predicted to interact with other proteins to mediate carbon reserve remobilization in response to MD treatment. Further correlation analysis revealed that the abundances of most of the differentially expressed proteins were not correlated with the corresponding transcript levels, indicating that the carbon reserve remobilization process was probably regulated by posttranscriptional modification. Our results provide insights into the molecular mechanisms underlying the regulation of carbon reserve remobilization from straw to grain in rice under MD conditions.

Global Survey of Alternative Splicing in Rice by Direct RNA Sequencing During Reproductive Development: Landscape and Genetic Regulation

“…TFs areimportant in controlling grain filling in crops. For example, transcription factor of NAC transactivates expression of starch synthesis gene in rice (Wang et al 2019a ). Rice basic leucine zipper factor and rice prolamin box binding factor activates the transcription of seed storage protein genes, which subsequently cause starch accumulation in seeds (Liu et al 2018a ).…”

“…Then, the above constructed vectors were mixed well for the transient expression assay in the rice protoplasts. This transient expression assay was performed as described previously (Wang et al 2019a , b ; Wang et al 2020 ). The primers used were listed in Additional file 2 : Table S5.…”

Analysis of Global Methylome and Gene Expression during Carbon Reserve Mobilization in Stems under Soil Drying

“…Then, the sugar extract was diluted to 50 mL with distilled water. The Suc content was measured as described in a previous study (Wang et al, 2020). The residue remaining in the centrifuge tube after sugar extraction was dried at 80°C for starch extraction using the HClO 4 reagent following the method described by Yang et al (2001).…”

Assessing Physiological and Genetic Evidence for Evolution of Shared Weedy Rice Traits at the Vegetative Growth Stage

“…(Table 4), many of these falling within the major and minor CHO metabolism MapMan pathway bins (Supplementary Table 15). The gene, LOC_Os01g64660 (Zhu et al, 2018;Wang et al, 2020), annotated as fructose-1,6-bisphosphatase, could be related to the higher level of fructose in leaf tissue in SH weeds when compared to indica cultivars (Table 2).…”