Sophisticated crosstalk of tryptophan-derived metabolites in plant stress responses.

Plants are frequently threatened by diverse stresses that severly impact their health and constrain crop productivity worldwide. Metabolic regulation serves as an important strategy for enhancing plant stress tolerance. Tryptophan, as a precursor of various plant natural products, including auxin, melatonin, and glucosinolates, plays a crucial role in maintaining plant health. To date, substantial progress has been made in elucidating tryptophan metabolism, particularly its involvement in improving plant stress tolerance. However, a systematic discussion of the crosstalk among tryptophan metabolites in protecting plants from stresses remains absent. Here, we explore tryptophan metabolism and its associated crosstalk regulation under stress conditions. We provide an overview of the biosynthesis and biofunctions of tryptophan metabolites, with a primary focus on their crosstalk in regulating plant stress resistance. The potential applications of tryptophan metabolism in stress adaptation are also examined. This work aims to establish a fundamental framework for understanding the regulatory roles of tryptophan metabolites in plant health and their mechanisms in sustainable agriculture.