The qLTG1.1 candidate gene CsGAI regulates low temperature seed germination in cucumber
The qLTG1.1 candidate gene CsGAI regulates low temperature seed germination in cucumber
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DOI：
10.1007/s00122-022-04097-w
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Xingfang Gu
中科院分区：
文献类型：
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作者：
Caixia Li;Shaoyun Dong;Diane M Beckles;Han Miao;Jiaqiang Sun;Xiaoping Liu;Weiping Wang;Shengping Zhang;Xingfang Gu
The CsGAI gene, identified by map-based, was involved in regulating seed germination in low temperature via the GA and ABA signaling pathways. Low temperature reduces the percentage of seeds germinating and delays seed germinating time, thus posing a threat to cucumber production. However, the molecular mechanism regulating low temperature germination in cucumber is unknown. We here dissected a major quantitative trait locus qLTG1.1 that controls seed germination at low temperature in cucumber. First, we fine-mapped qLTG1.1 to a 46.3-kb interval, containing three candidate genes. Sequence alignment and gene expression analysis identified Csa1G408720 as the gene of interest that was highly expressed in seeds, and encoded a highly conserved, low temperature-regulated DELLA family protein CsGAI. GUS expression analysis indicated that higher promoter activity underscored higher transcriptional expression of the CsGAI gene. Consistent with the known roles of GAI in ABA and GA signaling during germination, genes involved in the GA (CsGA2ox, CsGA3ox) and ABA biosynthetic pathways (CsABA1, CsABA2, CsAAO3 and CsNCED) were found to be differently regulated in the tolerant and sensitive genotypes under low temperatures, and this was reflected in differences in their ratio of GA-to-ABA. Based on these data, we proposed a working model explaining how CsGAI integrates the GA and ABA signaling pathways, to regulate cucumber seed germination at low temperature, thus providing new insights into this mechanism.
