OsATG10b, an autophagosome component, is needed for cell survival against oxidative stresses in rice.
Autophagy degrades toxic materials and old organelles, and recycles nutrients in eukaryotic cells. Whereas the studies on autophagy have been reported in other eukaryotic cells, its functioning in plants has not been well elucidated. We analyzed the roles of OsATG10 genes, which are autophagy-related. Two rice ATG10 genes - OsATG10a and OsATG10b - share significant sequence homology (about 75%), and were ubiquitously expressed in all organs examined here. GUS assay indicated that OsATG10b was highly expressed in the mesophyll cells and vascular tissue of younger leaves, but its level of expression decreased in older leaves. We identified T-DNA insertional mutants in that gene. Those osatg10b mutants were sensitive to treatments with high salt and methyl viologen (MV). Monodansylcadaverine-staining experiments showed that the number of autophagosomes was significantly decreased in the mutants compared with the WT. Furthermore, the amount of oxidized proteins increased in MV-treated mutant seedlings. These results demonstrate that OsATG10b plays an important role in the survival of rice cells against oxidative stresses.
Shin
Jun-Hye
JH
National Research Laboratory of Plant Functional Genomics, POSTECH Biotech Center, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, 790-784, Korea.
Yoshimoto
Kohki
K
Ohsumi
Yoshinori
Y
Jeon
Jong-Seong
JS
An
Gynheung
G
D000595:Amino Acid Sequence; D001343:Autophagy / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004269:DNA, Bacterial; D018076:DNA, Complementary / Q000302:isolation & purification; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005966:Glucuronidase / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D012275:Oryza / Q000166:cytology* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D010269:Paraquat / Q000494:pharmacology; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism
D004269:DNA, Bacterial; D018076:DNA, Complementary; D010940:Plant Proteins; C036483:T-DNA; D012965:Sodium Chloride; D005966:Glucuronidase; D010269:Paraquat