title: AtEXP2 is involved in seed germination and abiotic stress response in Arabidopsis.
abstract: Expansins are cell wall proteins that promote cell wall loosening by inducing pH-dependent cell wall extension and stress relaxation. Expansins are required in a series of physiological developmental processes in higher plants such as seed germination. Here we identified an Arabidopsis expansin gene AtEXPA2 that is exclusively expressed in germinating seeds and the mutant shows delayed germination, suggesting that AtEXP2 is involved in controlling seed germination. Exogenous GA application increased the expression level of AtEXP2 during seed germination, while ABA application had no effect on AtEXP2 expression. Furthermore, the analysis of DELLA mutants show that RGL1, RGL2, RGA, GAI are all involved in repressing AtEXP2 expression, and RGL1 plays the most dominant role in controlling AtEXP2 expression. In stress response, exp2 mutant shows higher sensitivity than wild type in seed germination, while overexpression lines of AtEXP2 are less sensitive to salt stress and osmotic stress, exhibiting enhanced tolerance to stress treatment. Collectively, our results suggest that AtEXP2 is involved in the GA-mediated seed germination and confers salt stress and osmotic stress tolerance in Arabidopsis.
authors.affiliation: Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: An
authors.initials: A
authors.lastname: Yan
authors.affiliation: Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Minjie
authors.initials: M
authors.lastname: Wu
authors.affiliation: Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Limei
authors.initials: L
authors.lastname: Yan
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Hu
authors.affiliation: Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Imran
authors.initials: I
authors.lastname: Ali
authors.affiliation: Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Gan
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000235:genetics*; D009997:Osmotic Pressure; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified; D055049:Salt Tolerance / Q000235:genetics; D012639:Seeds / Q000235:genetics* / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; C095825:expansin protein, plant