TY - JOUR T1 - CYP20-3 deglutathionylates 2-CysPRX A and suppresses peroxide detoxification during heat stress JF - Life Science Alliance JO - Life Sci. Alliance DO - 10.26508/lsa.202000775 VL - 3 IS - 9 SP - e202000775 AU - Wenshan Liu AU - Izailda Barbosa dos Santos AU - Anna Moye AU - Sang-Wook Park Y1 - 2020/09/01 UR - https://www.life-science-alliance.org/content/3/9/e202000775.abstract N2 - In plants, growth-defense trade-offs occur because of limited resources, which demand prioritization towards either of them depending on various external and internal factors. However, very little is known about molecular mechanisms underlying their occurrence. Here, we describe that cyclophilin 20-3 (CYP20-3), a 12-oxo-phytodienoic acid (OPDA)–binding protein, crisscrosses stress responses with light-dependent electron reactions, which fine-tunes activities of key enzymes in plastid sulfur assimilations and photosynthesis. Under stressed states, OPDA, accumulates in the chloroplasts, binds and stimulates CYP20-3 to convey electrons towards serine acetyltransferase 1 (SAT1) and 2-Cys peroxiredoxin A (2CPA). The latter is a thiol-based peroxidase, protecting and optimizing photosynthesis by reducing its toxic byproducts (e.g., H2O2). Reduction of 2CPA then inactivates its peroxidase activity, suppressing the peroxide detoxification machinery, whereas the activation of SAT1 promotes thiol synthesis and builds up reduction capacity, which in turn triggers the retrograde regulation of defense gene expressions against abiotic stress. Thus, we conclude that CYP20-3 is a unique metabolic hub conveying resource allocations between plant growth and defense responses (trade-offs), ultimately balancing optimal growth phonotype. ER -