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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #339601

Research Project: Genetic Enhancement of Allium, Cucumis, and Daucus Germplasm

Location: Vegetable Crops Research

Title: The major-effect quantitative trait locus CsARN6.1 encodes an AAA ATPase domain-containing protein that is associated with waterlogging stress tolerance by promoting adventitious root formation

Author
item Xu, Xuewen - Yangzhou University
item Ji, Jing - Yangzhou University
item Xu, Qiang - Yangzhou University
item Qi, Xiaohua - Yangzhou University
item Weng, Yiqun
item Chen, Xuehao - Yangzhou University

Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2017
Publication Date: 1/8/2018
Citation: Xu, X., Ji, J., Xu, Q., Qi, X., Weng, Y., Chen, X. 2018. The major-effect quantitative trait locus CsARN6.1 encodes an AAA ATPase domain-containing protein that is associated with waterlogging stress tolerance by promoting adventitious root formation. Plant Journal. 93:917–930. https://doi.org/10.1111/tpj.13819.
DOI: https://doi.org/10.1111/tpj.13819

Interpretive Summary: In plants, the formation of hypocotyl-derived adventitious roots (AR) is an important morphological acclimation to waterlogging stress; however, its genetic basis remains fragmentary. In the present study, through combined use of bulked segregant analysis-based high throughput next-gen whole genome sequencing, SNP haplotyping as well as fine genetic mapping, we identified a candidate gene for a major-effect QTL ARN6.1 that is responsible for waterlogging tolerance due to increased adventitious root formation in the cucumber line Zaoer-N. Through multiple lines of evidence, we show that the cucumber gene Csa6G504460 was the most possible candidate for ARN6.1 which encodes an AAA (ATPase associated with various cellular activities) ATPase that was located mainly in the cytosol. The increased expression of this candidate gene and increased AR formation under waterlogging in Zaoer-N could be attributed to a non-synonymous SNP in the coiled-coil domain region of this gene. Csa6G504460 regulates the ARN phenotype via its ATPase activity. The mutation inside the candidate gene was responsible for the loss of the ATPase activity in the susceptible line Pepino, which was strong and dose-dependent in the waterlogging tolerant Zaoer-N. Ectopic expression of Csa6G504460 in Arabidopsis resulted in better rooting ability and lateral root development in the transgenic plants. Taken together, these data support the AAA-type ATPase Csa6G504460 as a novel player in regulating AR regulation and waterlogging tolerance in cucumber.

Technical Abstract: In plants, the formation of hypocotyl-derived adventitious roots (AR) is an important morphological acclimation to waterlogging stress, but its genetic basis is largely unknown. In the present study, with combined use of bulked segregant analysis-based high throughput next-gen whole genome sequencing, SNP haplotyping and fine genetic mapping, we identified a candidate gene for a major-effect QTL ARN6.1 that is responsible for waterlogging tolerance due to increased adventitious root formation in the cucumber line Zaoer-N. We provided multiple lines of evidence to show that the cucumber gene Csa6G504460 was the most possible candidate for ARN6.1 which encodes an AAA ATPase protein. The increased expression of this candidate gene and increased AR formation under waterlogging in Zaoer-N could be attributed to a non-synonymous SNP inside a functional domain of this gene. We show that Csa6G504460 regulates the ARN phenotype via its ATPase activity. Our support the AAA-type ATPase Csa6G504460 as a novel player in regulating AR regulation and waterlogging tolerance in cucumber.