Nitric Oxide Enhancing Resistance to PEG-Induced Water Deficiency is Associated with the Primary Photosynthesis Reaction in Triticum aestivum L.

Abstract

Photosynthesis is affected by water-deficiency (WD) stress, and nitric oxide (NO) is a free radical that participates in the photosynthesis process. Previous studies have suggested that NO regulates excitation-energy distribution of photosynthesis under WD stress. Here, quantitative phosphoproteomic profiling was conducted using iTRAQ. Differentially phosphorylated protein species (DEPs) were identified in leaves of NO- or polyethylene glycol (PEG)-treated wheat seedlings (D), and in control seedlings. From 1396 unique phosphoproteins, 2257 unique phosphorylated peptides and 2416 phosphorylation sites were identified. Of these, 96 DEPs displayed significant changes (≥1.50-fold, p < 0.01). These DEPs are involved in photosynthesis, signal transduction, etc. Furthermore, phosphorylation of several DEPs was upregulated by both D and NO treatments, but downregulated only in NO treatment. These differences affected the chlorophyll A–B binding protein, chloroplast post-illumination chlorophyll-fluorescence-increase protein, and SNT7, implying that NO indirectly regulated the absorption and transport of light energy in photosynthesis in response to WD stress. The significant difference of chlorophyll (Chl) content, Chl a fluorescence-transient, photosynthesis index, and trapping and transport of light energy further indicated that exogenous NO under D stress enhanced the primary photosynthesis reaction compared to D treatment. A putative pathway is proposed to elucidate NO regulation of the primary reaction of photosynthesis under WD.

Genome-wide association study and selection for field resistance to cassava root rot disease and productive traits

“…11G056800 . 1 is the coder for post-illumination chlorophyll fluorescence increase protein, which is associated with the response to photoinhibition under water deficit conditions [ 64 ]. Although they primarily affect the roots of cassava [ 17 ] and influence water absorption, the fungi associated with root rot can colonize the plant stems [ 29 ], thereby blocking the flow of sap and causing withering in the shoot, yield, and even the death of the plant.…”

Maize metabolome and proteome responses to controlled cold stress partly mimic early‐sowing effects in the field and differ from those of Arabidopsis

“…For instance, its phosphorylation of thylakoid proteins contributes to maintaining the structure of the photosynthetic machinery, balancing excitation between PSII and PSI, and signalling by controlling redox balance in the electron transfer chain (Tikkanen, Gollan, Suorsa, Kangasjarvi, & Aro, 2012). SNT7 kinase was shown to be up‐regulated in response to drought stress in wheat (Shao et al, 2018). Its downregulation in the present work, in parallel with the regulation of chlorophyll accumulation observed, may lead to an increase in the PSI‐to‐PSII ratio during thylakoid membrane biogenesis and contribute to a complex regulation of ROS signalling (Tikkanen et al, 2012).…”

Autophagic Survival Precedes Programmed Cell Death in Wheat Seedlings Exposed to Drought Stress

“…Additionally, we use PEG-8000 simulated drought, and in most experiments, 20% concentration was selected because many existing methods for managing substrate water potential have employed PEG to simulate a specific water deficit exposure [25,26]; in wheat seedlings, concentrations of 20% PEG are often selected for related experiments [27,28,29]. Moreover, in our study, 20% PEG-8000 promoted autophagy later than 24 h. Therefore, wheat seedlings were not killed in a short time.…”