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CATALASE2 functions for seedling postgerminative growth by scavenging H 2 O 2 and stimulating ACX2/3 activity in Arabidopsis
Author(s) -
Liu WenCheng,
Han TongTong,
Yuan HongMei,
Yu ZhenDong,
Zhang LinYu,
Zhang BingLei,
Zhai Shuang,
Zheng SiQiu,
Lu YingTang
Publication year - 2017
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.13031
Subject(s) - seedling , elongation , mutant , biology , catalase , wild type , biochemistry , oxidative stress , horticulture , materials science , gene , metallurgy , ultimate tensile strength
Increased fatty acid β‐oxidation is essential for early postgerminative growth in seedlings, but high levels of H 2 O 2 produced by β‐oxidation can induce oxidative stress. Whether and how catalase (CAT) functions in fine‐tuning H 2 O 2 homeostasis during seedling growth remain unclear. Here, we report that CAT2 functions in early seedling growth. Compared to the wild type, the cat2‐1 mutant, with elevated H 2 O 2 levels, exhibited reduced root elongation on sucrose (Suc)‐free medium, mimicking soils without exogenous sugar supply. Treatment with the H 2 O 2 scavenger potassium iodide rescued the mutant phenotype of cat2‐1 . In contrast to the wild type, the cat2‐1 mutant was insensitive to the CAT inhibitor 3‐amino‐1,2,4‐triazole in terms of root elongation when grown on Suc‐free medium, suggesting that CAT2 modulates early seedling growth by altering H 2 O 2 accumulation. Furthermore, like cat2‐1 , the acyl‐CoA oxidase (ACX) double mutant acx2‐1 acx3‐6 showed repressed root elongation, suggesting that CAT2 functions in early seedling growth by regulating ACX activity, as this activity was inhibited in cat2‐1 . Indeed, decreased ACX activity and short root of cat2‐1 seedlings grown on Suc‐free medium were rescued by overexpressing ACX3 . Together, these findings suggest that CAT2 functions in early seedling growth by scavenging H 2 O 2 and stimulating ACX2/3 activity.