High light and temperature reduce photosynthetic efficiency through different mechanisms in the C4 model Setaria viridis

Abstract

C4 plants frequently experience high light and high temperature conditions in the field, which reduce growth and yield. However, the mechanisms underlying these stress responses in C4 plants have been under-explored, especially the coordination between mesophyll (M) and bundle sheath (BS) cells. We investigated how the C4 model plant Setaria viridis responded to a four-hour high light or high temperature treatment at photosynthetic, transcriptomic, and ultrastructural levels. Although we observed a comparable reduction of photosynthetic efficiency in high light or high temperature treated leaves, detailed analysis of multi-level responses revealed important differences in key pathways and M/BS specificity responding to high light and high temperature. We provide a systematic analysis of high light and high temperature responses in S. viridis, reveal different acclimation strategies to these two stresses in C4 plants, discover unique light/temperature responses in C4 plants in comparison to C3 plants, and identify potential targets to improve abiotic stress tolerance in C4 crops.

Systems-wide analysis revealed shared and unique responses to moderate and acute high temperatures in the green alga Chlamydomonas reinhardtii

“…Grid type was set as “point” with a sampling step of 500×500 pixels and pattern size of 15×15 pixels. The percent of relative volume for mitochondria was collected after identifying all grid points within one cell and further analyzed in excel 19 . TEM images with a magnification of 8 K were used in the Fiji (ImageJ, FIJI software, National Institutes of Health) analysis.…”

“…Furthermore, high temperatures can decrease the stability of RNAs and alter the transcriptomic landscape of cells under heat stress 14 . Additionally, high temperature can cause damage to photosynthetic electron transport chains, reducing photosynthetic efficiency 15 – 19 , and leading to increased reactive oxygen species (ROS) accumulation 4 , 20 , 21 . Heat-induced ROS production increases DNA damage and the need for DNA repair pathways, although the mechanisms of these processes are poorly understood 10 , 22 .…”

Chloroplast Protein Tic55 Involved in Dark-Induced Senescence through AtbHLH/AtWRKY-ANAC003 Controlling Pathway of Arabidopsis thaliana

“…Both temperature and light have significant effects on the chloroplast development and chlorophyll biosynthesis. Recent studies have reported that chill stress and heat stress impaired chlorophyll biosynthesis due to the down-regulation of gene expression and protein abundance of several enzymes implicated in the tetrapyrrole metabolism [ 51 ]. Furthermore, Aronsson et al [ 52 ] showed that the generation of the Toc33 mutant ppi1 was related to the intense light stress, resulting in the reduced chlorophyll production, when compared to the WT.…”

“…Of the repressed transcripts in tic55-II mutant compared with wild type, two-fold change ( tic55-II /WT) or greater in gene expression were selected for further investigation ( Table 1 ). Namely three groups, including ANAC (NAM/ATAF1, 2/CUC2), AtWRKY, and AtbHLH family of transcription factors (TFs) in controlling the stress and senescence responses in Arabidopsis [ 12 , 17 , 28 , 29 , 30 , 39 , 40 , 49 , 51 , 54 , 55 ], are demonstrated in Table 2 .…”

Design and Analysis of Native Photorespiration Gene Motifs of Promoter Untranslated Region Combinations Under Short Term Abiotic Stress Conditions

“…Although, considerable progress has been made to biochemically characterize the genes involved in photorespiration the mechanism of regulation of these genes in response to unavoidable environmental cues is at its inception ( Laxa and Fromm, 2018 ). A number of recent reports have suggested that key photorespiratory genes, including PLGG1 , GOX1 , PGLP1 , HPR1 are differentially regulated by elevated temperature and high light intensity ( Song et al, 2014 ; Balfagón et al, 2019 ; Timm et al, 2019 ; Anderson et al, 2021 ; Moore et al, 2021 ).…”