Cover image: Pictured is a male Dendropsophus bifurcus treefrog in Yasuni, Ecuador. Justin Touchon et al. explored the evolution of terrestrial reproduction through field experiments and phylogenetic analysis involving 13 species of Central and South American treefrogs in the genus Dendropsophus. Six of the species demonstrated previously undocumented degrees of flexibility in laying eggs in either terrestrial or aquatic environments, depending on environmental conditions. The results suggested that behavioral flexibility in egg-laying location likely preceded the evolution of eggs physically adapted to exclusively terrestrial reproduction. See the article by Touchon et al. e2312371121. Image credit: Justin Touchon.
JIPB:以色列科学家揭示植物响应氧化胁迫的新机制
Cysteine是谷胱甘肽和蛋氨酸合成的前体物质。本研究发现，在氧化胁迫条件下，蛋氨酸和半胱氨酸存在竞争关系。随着氧化型的 glutathione (GSSG) 水平的增加会导致蛋氨酸的合成显著下降。
GSSG 可以结合cystathionine γ-synthase（a key enzyme in the methionine synthesis pathway）并将其降解，这会导致以蛋氨酸为前体物质的代谢流被抑制，从而更多的代谢流转向谷胱甘肽的合成，从而提高植物的抗氧化能力。
小结：本研究揭示了在胁迫条件下半胱氨酸、谷胱甘肽及蛋氨酸的相互关系。
原文：Sulfur metabolism under stress: Oxidized glutathione inhibits methionine biosynthesis by destabilizing the enzyme cystathionine γ-synthase
