Modulation of TCA Cycle and Enzymes During Different Environmental Stresses

Tricarboxylic acid cycle (TCA) is an important metabolic cycle as it facilitates the synthesis of ATP through catabolic pathways. The essential signaling functions of mitochondria include the mitochondrial regulation of autophagy through AMP-activated protein kinase which induces autophagy, thus triggering the release of Ca²⁺ in endoplasmic reticulum which enhances the TCA cycle. The structure and functionality of eight different enzymes 310of TCA cycle inside the mitochondrial matrix, linked with oxidation and reduction products associated with it, facilitate the structures and operations of the TCA cycle. Considering the application of TCA cycle inside the plant body, the carrier for pyruvate into the matrix is unidentified till now. Despite this, this study will broaden the horizons on the interconnectedness of photosynthesis, root development, and various other heterotrophic tissues with TCA cycle. During the study of genomic organization of the enzymes, major genes were found to be subcellular and localized in mitochondria followed by cytosol, peroxisomes, and chloroplasts. Using metabolic control analysis, flux control analysis of respiration was quantified at steady state which associates the quantity of a particular enzyme with respiration rate. Comprehension of complex pathways of metabolism and regulation of TCA activity as well as in vivo regulation requires intensive effort to correlate with photorespiration, nitrate assimilation, and photosynthesis. Environmental effect like high temperature or increased daylight reduces net carbon because it increases the plant respiration, not photosynthesis. Ecological hassle, for example, floods lead to low availability of molecular oxygen, differing levels of enzymes obstruct or stimulate certain processes impacting respiration, or may cause mutation leading to suppressed immunity or cancer, as with the case of HIF-α regulation, and aluminum toxicity which evokes dysfunctionality. These studies show that modulating TCA cycle and its enzymes by environmental and/or intrinsic factors affects various biological processes.