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NYEs/SGRs‐mediated chlorophyll degradation is critical for detoxification during seed maturation in Arabidopsis
Author(s) -
Li Zhongpeng,
Wu Shouxin,
Chen Junyi,
Wang Xiaoyan,
Gao Jiong,
Ren Guodong,
Kuai Benke
Publication year - 2017
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13710
Subject(s) - arabidopsis , chlorophyll , germination , detoxification (alternative medicine) , mutant , ripening , biology , senescence , arabidopsis thaliana , botany , limiting , degradation (telecommunications) , horticulture , microbiology and biotechnology , gene , biochemistry , medicine , mechanical engineering , alternative medicine , pathology , computer science , engineering , telecommunications
Summary In the seed industry, chlorophyll (Chl) fluorescence is often used as a major non‐invasive reporter of seed maturation and quality. Breakdown of Chl is a proactive process during the late stage of seed maturation, as well as during leaf senescence and fruit ripening. However, the biological significance of this process is still unclear. NYE 1 and NYE 2 are Mg‐dechelatases, catalyzing the first rate‐limiting step of Chl a degradation. Loss‐of‐function of both NYE 1 and NYE 2 not only results in a nearly complete retention of Chl during leaf senescence, but also produces green seeds in Arabidopsis. In this study, we showed that Chl retention in the nye1 nye2 double‐mutant caused severe photo‐damage to maturing seeds. Upon prolonged light exposure, green seeds of nye1 nye2 gradually bleached out and eventually lost their germination capacity. This organ‐specific photosensitive phenotype is likely due to an over‐accumulation of free Chl, which possesses photosensitizing properties and causes a burst of reactive oxygen species upon light exposure. As expected, a similar, albeit much milder, photosensitive phenotype was observed in the seeds of d1 d2 , a green‐seed mutant defective in NYE / SGR orthologous genes in soybean. Taken together, our data suggest that efficient NYE s‐mediated Chl degradation is critical for detoxification during seed maturation.