Question

what are the Effect of CO2 on Arabidopsis and how does it respond to the stress conditions

Answer 1

Effect of CO2 on Arabidopsis

1. Total shoot biomass, seed formation increases at an elevated level of CO2; however, flowering architecture is not affected by CO2.
2. Soluble sugar content is not affected by the elevated levels of CO2 while starch concentration is increased in the shoot. Because of increased starch content, total nitrogen content (dry mass basis) is decreased.
3. No acclimation to the photosynthesis was observed; however, photosynthesis is stimulated at the elevated CO2 level.
4. Reproductive efficiency and fitness are increased at elevated CO2 levels.   

The following three mechanisms are suggested to plays an active role during heat, osmotic shock, and high salinity (figure).

1. High temperatures lead to protein misfolding and aggregation. The hydrophobic patch of the misfolded protein is detected by (Heat sensitive protein) HSPs, which then induce expression of heat-related genes through HSE.
2. A variety of transmembrane proteins are known to be feeling the drought. OSCA1 is presumed to be triggered by elevated membrane tension that occurs during osmotic stress. This results in calcium inflow to mediate downstream signals. Another protein called CSC1 (homolog of OSCA1) is also described as a calcium channel regulated with osmotic stress. HK domain of TSC also plays a vital role in osmotic stress. TSC (two-component systems) has two domains His kinase (HK) and signaling kinase (SK). His kinase (HK) domain of the TSC protein undergoes phosphorylation at Histidine residue and becomes activated in the presence of osmotic stress. This activated HK then phosphorylate regulatory protein and initiate downstream signaling response for osmatic stress.
3. In the presence of high salinity, the SOS pathway activates by an increased level of calcium. The calcium level is increased due to the binding (sodium) of monovalent cations to the negatively charged GlcA of the GIPC (Glycosyl Inositol Phosphoryl Ceramides) sphingolipids. The activated SOS pathway will remove increase sodium from the cell.

Heat if bde Protein 192 Nucieus. calciu HSE Calcium. cell woll GIPC - calcium. Sos-3 salinity OSCAT Regulatory Profin sos-2 Nat SOSI th SK osmotic Drought TSC