A mutation in CsHD encoding a histidine and aspartic acid domain-containing protein leads to yellow young leaf-1 (yyl-1) in cucumber (Cucumis sativus L.). (April 2020)

• Record Type: Journal Article
• Authors: Hu, Liangliang; Zhang, Haiqiang; Xie, Chen; Wang, Jin; Zhang, Jiayu; Wang, Hui; Weng, Yiqun; Chen, Peng; Li, Yuhong
• Is Part Of: Plant science. Volume 293(2020)
• Publication Date: 2020-04
• Subjects: YYL-1 yellow young leaf-1 -- HD histidine and aspartic acid -- Chl Chlorophyll -- GluRS glutamyl-tRNA synthetase -- BSA bulked segregation analysis -- TEM transmission electron microscopy -- SSR Simple Sequence Repeats -- SNPs single nucleotide polymorphisms -- Indels insertion or deletion of bases -- cDNA complementary deoxyribonucleic acid -- qPCR quantitative PCR -- VIGS virus-induced gene silencing; Cucumber -- Leaf color -- Virescent leaf -- Yellow young leaf -- Mutant -- CsHD; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2020.110407
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: We identified a chlorophyll-deficient, virescent mutant, yyl-1 in cucumber. CsHD is the candidate gene for Yyl-1 that encodes a histidine and aspartic acid domain-containing protein. The yellow young leaf is due to a nonsense mutation in CsHD . This is first report that CsHD involved in the chlorophyll bisoynthesis and chloroplast development in the horticultural crops. Abstract: Leaf color mutants are an ideal tool to study chlorophyll biosynthesis, chloroplast development and photosynthesis. In this study, we identified an EMS-induced yellow young leaf mutant C777. The mutant exhibited yellow cotyledons and emerging true leaves with stay-green dots that turn green gradually with leaf growth. Segregation analysis in several populations indicated that the mutant C777 was controlled by a recessive gene yyl-1. Fine mapping delimited the yyl-1 locus to a 45.3 kb region harboring 8 putative genes, but only one SNP (G to A) was identified between C777 and its wild-type parental line in this region which occurred in the 13 th exon of CsHD that encodes a histidine and aspartic acid (HD) domain containing protein. This nonsense mutation introduced a stop codon and thus a premature protein. Uniqueness of this mutant allele was verified in 515 cucumber lines. Quantitative real-time PCR revealed significantly reduced expression of CsHD gene in the mutant. Further, silencing the NbHD gene by VIGS in tobacco resulted in virescent young leaves and significantly down-regulated expression of HD gene. These results strongly supported the association of the CsHD gene with the virescent young leaf phenotype in C777. This is the first report to clone and characterize the C sHD gene in the horticultural crops. The results may help understand the functions of the HD gene in chloroplast development and chlorophyll biosynthesis in plants.