A barley homolog of yeast ATG6 is involved in multiple abiotic stress responses and stress resistance regulation.
Autophagy is a highly conserved degradation pathway among eukaryote cells, which can recycle damaged or unwanted cell materials upon encountering stress conditions. As a key component of the Class III PI3K kinase complex, ATG6/Beclin-1 is essential for autophagosome formation. In this study, we isolated a putative HvATG6 gene in barley genome. The protein encoded by HvATG6 shares high sequence identity to ATG6 orthologs in rice and wheat, and has a typical autophagy-specific domain containing segments of repeated β-sheet-α-helix. The expression of HvATG6 protein restored the appearance of autophagosomes in yeast atg6 mutant, indicating that HvATG6 complements the deficiency of yeast ATG6 protein in autophagy. Punctate florescence signals, considered as the PAS for autophagosome initiation, were observed in the cytoplasm of cells when HvATG6-GFP fusion construct was transformed into barley protoplast. Furthermore, the expression of HvATG6 was upregulated by various abiotic stresses including dark, H2O2treatment, nitrogen deficiency, high salinity, drought, low temperature and toxic aluminum. Knockdown of HvATG6 in barley leaves through barley strip mosaic virus (BSMV)-induced gene silencing led to accelerated yellowing under dark and H2O2treatments. Based on the above findings, we propose that barley ATG6 plays the similar role as other plant ATG6 orthologs, and might be involved in stress-induced autophagy process.
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Xiaowei
X
Zeng
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Zhanghui
Z
Zeng
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Cuicui
C
Liu
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Weiyi
W
Yuan
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Ning
N
Hou
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Hongwu
H
Bian
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Muyuan
M
Zhu
Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China. Electronic address: ninghan@zju.edu.cn.
Ning
N
Han
D000595:Amino Acid Sequence; D000071182:Autophagosomes; D000071186:Beclin-1 / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D020868:Gene Silencing; D001467:Hordeum / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D018515:Plant Leaves; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology*; D014026:Nicotiana
D000071186:Beclin-1
ATG6; Abiotic stress; Autophagy; Barley; PI3K; VIGS