Plants are exposed to various environmental cues that lead to reactive oxygen species (ROS) accumulation. ROS production and detoxification are tightly regulated to maintain balance. Although studies of glucose (Glc) are always accompanied by ROS in animals, the role of Glc in respect of ROS in plants is unclear. We isolated gsm2 (Glc-hypersensitive mutant 2), a mutant with a notably chlorotic-cotyledon phenotype. The chloroplast-localized GSM2 was characterized as a transaldolase in the pentose phosphate pathway. With 3% Glc treatment, fewer or no thylakoids were observed in gsm2 cotyledon chloroplasts than in wild-type cotyledon chloroplasts, suggesting that GSM2 is required for chloroplast protection under stress. gsm2 also showed evaluated accumulation of ROS with 3% Glc treatment and was more sensitive to exogenous H₂O₂ than the wild type. Gene expression analysis of the antioxidant enzymes in gsm2 revealed that chloroplast damage to gsm2 cotyledons results from the accumulation of excessive ROS in response to Glc. Moreover, the addition of diphenyleneiodonium chloride or phenylalanine can rescue Glc-induced chlorosis in gsm2 cotyledons. This work suggests that GSM2 functions to maintain ROS balance in response to Glc during early seedling growth and sheds light on the relationship between Glc, the pentose phosphate pathway and ROS.

植物会受到各种环境因素的影响，从而导致活性氧（ROS）积累。严格控制ROS的产生和排毒，以保持平衡。尽管在动物中对葡萄糖（Glc）的研究总是伴随着ROS，但尚不清楚Glc在植物中对ROS的作用。我们分离GSM2（ģ LC-超小号ensitive米utant 2），其突变体具有显着褪绿-子叶表型。叶绿体定位的GSM2被表征为磷酸戊糖途径中的转醛酶。使用3％Glc处理时，在gsm2中观察到的类囊体更少或没有子叶的叶绿体比野生型子叶的叶绿体要好，这表明在胁迫下需要GSM2来保护叶绿体。gsm2还显示了经过3％Glc处理的ROS累积评估，并且对野生型H ₂ O _2的敏感性高于野生型。对gsm2中抗氧化酶的基因表达分析表明，叶绿体对gsm2子叶的损害是由于响应Glc积累了过量的ROS所致。在此外，添加的diphenyleneiodonium酰氯或苯丙氨酸可以拯救GLC诱发萎黄GSM2子叶。这项工作表明，GSM2的功能是在幼苗早期生长期间响应Glc来维持ROS平衡，并阐明Glc，戊糖磷酸途径与ROS之间的关系。