Red-fleshed kiwifruit, valued for its high anthocyanin content and associated health benefits, is increasingly threatened by rising temperatures. Global warming severely inhibits anthocyanin accumulation, leading to flesh discoloration and nutrient loss, directly compromising fruit quality and the sustainable development of the industry.

To address this challenge, researchers from the Wuhan Botanical Garden of the Chinese Academy of Sciences used "Hongyang" kiwifruit to simulate high-temperature stress (30°C, 35°C, 40°C, compared with a 25°C control). They systematically monitored physiological indicators, transcriptome characteristics, and dynamic changes in related metabolites to clarify how high-temperature stress affects anthocyanin biosynthesis and stability, providing a theoretical basis for developing fruit quality regulation strategies under high-temperature conditions.

The study found that rising temperatures (25–40°C) significantly induced branch in the anthocyanin biosynthesis pathway, while the degradation rate of anthocyanins accelerated with increasing temperature, shortening their half-life. High temperatures promoted the accumulation of degradation products such as protocatechuic acid and activated the expression of degradation enzyme genes including laccase and β-glucanase.

This study is the first to establish a kinetic model of anthocyanin metabolism in living tissue (fruit flesh), confirming that under high-temperature conditions, the metabolic flow in the phenylpropanoid pathway of kiwifruit is redirected. The combined effect of suppressed anthocyanin biosynthesis and accelerated degradation results in a marked decrease in anthocyanin accumulation.

These findings not only offer new insights into the mechanisms of plant anthocyanin biodegradation but also provide a theoretical basis for molecular breeding aimed at regulating fruit color.

The study was recently published in Plant Physiology and Biochemistry. It was supported by the National Natural Science Foundation of China, the Hubei Provincial Natural Science Foundation of China, and other funding sources.