PEPC of sugarcane regulated glutathione S-transferase and altered carbon–nitrogen metabolism under different N source concentrations in Oryza sativa

Abstract

Background Phosphoenolpyruvate carboxylase (PEPC) plays an important role in the primary metabolism of higher plants. Several studies have revealed the critical importance of PEPC in the interaction of carbon and nitrogen metabolism. However, the function mechanism of PEPC in nitrogen metabolism is unclear and needs further investigation. Results This study indicates that transgenic rice expressing the sugarcane C4-PEPC gene displayed shorter primary roots and fewer crown roots at the seedling stage. However, total nitrogen content was significantly higher in transgenic rice than in wild type (WT) plants. Proteomic analysis revealed that there were more differentially expressed proteins (DEPs) responding to nitrogen changes in transgenic rice. In particular, the most enriched pathway “glutathione (GSH) metabolism”, which mainly contains GSH S-transferase (GST), was identified in transgenic rice. The expression of endogenous PEPC, GST and several genes involved in the TCA cycle, glycolysis and nitrogen assimilation changed in transgenic rice. Correspondingly, the activity of enzymes including GST, citrate synthase, 6-phosphofructokinase, pyruvate kinase and ferredoxin-dependent glutamate synthase significantly changed. In addition, the levels of organic acids in the TCA cycle and carbohydrates including sucrose, starch and soluble sugar altered in transgenic rice under different nitrogen source concentrations. GSH that the substrate of GST and its components including glutamic acid, cysteine and glycine accumulated in transgenic rice. Moreover, the levels of phytohormones including indoleacetic acid (IAA), zeatin (ZT) and isopentenyladenosine (2ip) were lower in the roots of transgenic rice under total nutrients. Taken together, the phenotype, physiological and biochemical characteristics of transgenic rice expressing C4-PEPC were different from WT under different nitrogen levels. Conclusions Our results revealed the possibility that PEPC affects nitrogen metabolism through regulating GST, which provide a new direction and concepts for the further study of the PEPC functional mechanism in nitrogen metabolism.

Understanding complex genetic architecture of rice grain weight through QTL-meta analysis and candidate gene identification

“…Several of these genes were not annotated, and only 25 of them, were to be found characterized and annotated. These included important genes like GSTL3 ( LOC _ Os03g17460 ) and GSTL1 ( LOC_Os03g17480 ) responsible for stress tolerance 39 , 40 , while PRR73 ( LOC_Os03g17570 ) regulates salt tolerance 41 in rice. However, these characterized genes are not related to grain weight and are instead associated with some important biological processes.…”

Estimation of intrinsic water-use efficiency from δ13C signature of C3 leaves: Assumptions and uncertainty

“…But it is also suggested that the PEPC carboxylation could be important under the conditions of low stomatal conductance or carboxylation in darkness ( Ikeda and Yamada, 1981 ; Gupta et al., 1994 ; Hibberd and Quick, 2002 ). Furthermore, several studies have revealed that N source and concentration were potential factors affecting carbon fixation by PEPC, which indicates that b’ could vary with nitrogen metabolism ( Raven and Farquhar, 1990 ; Douthe et al., 2012 ; Lian et al., 2021 ). That is, Equation 14 is not particularly useful for iWUE estimation because β is variable and difficult to quantify.…”

The complex stress of waterlogging and high temperature accelerated maize leaf senescence and decreased photosynthetic performance at different growth stages

“…Thus, we speculated that waterlogging stress at the early stages indirectly reduced photosynthetic intensity by inhibiting root aerobic respiration (Jackson & Colme, 2005; Phukan et al., 2015). High temperature stress directly reduces photosynthetic intensity by disrupting plant leaf functions, and then preventing photosynthetic electron transfer and photosynthetic carbon sequestration process (Lian et al., 2021; Zhang et al., 2022). Our results suggested that the function of leaves was more sensitive to waterlogging stress during the V3 and V6 stages and more sensitive to high temperature stress during the VT stage.…”