Fine mapping and candidate gene analysis of Brtri1, a gene controlling trichome development in Chinese cabbage (Brassica rapa L. ssp pekinensis)

Abstract

Trichomes are derived from the epidermis and constitute an ideal system for studying cell division in plants. Here, a Chinese cabbage doubled haploid (DH) line (FT) without trichomes was crossed with another DH line (PurDH-1) with trichomes to develop an F population for fine mapping of trichome control genes. Genetic analysis showed that the trichome phenotype was controlled by a single dominant gene, Brtri1. Using 1226 glabrous individuals in the F segregation population, Brtri1 was localized to a 16.84 kb region between markers Pur6-31 and Pur6-39 on chromosome A06. One of the four complete open reading frames within the mapping region, Bra025311, encodes a MYB transcription factor and is highly homologous to the trichome regulatory gene GL1 in Arabidopsis thaliana. It was thus regarded as a candidate gene for Brtri1. Comparative sequencing showed a 5-bp deletion in the third exon of Bra025311 in FT, resulting in a frame-shift mutation. No expression of Bra025311 was detected in FT. A co-dominant indel marker close to this mutation site was developed for marker-assisted selection in Chinese cabbage breeding.

Genetic and Transcriptome Analysis of Leaf Trichome Development in Chinese Cabbage (Brassica rapa L. subsp. pekinensis) and Molecular Marker Development

“…In another report by the same authors in 2013, they discovered that the large variation of the 3′-terminal of GL1a may be critical for leaf hair traits of the hairless and hairy lines of Raphanus sativus [ 5 ]. Simple sequence repeat (SSR) markers were analyzed using a large-scale F 2 population, based on which Bra025311 , a close homolog to GL1 of Arabidopsis thaliana , was identified as a candidate gene controlling the trichome trait in Chinese cabbage [ 35 ]. QTL analysis was performed on a hairy line, Mibuna, and a hairless line, Mizuna, of Chinese cabbage.…”

A novel HD‐Zip I/C2H2‐ZFP/WD‐repeat complex regulates the size of spine base in cucumber

“…The bHLH transcription factor SlMYC1 and the receptor of plant hormone jasmonate JAI‐1 appear to modulate the density and morphogenesis of glandular type VI trichomes (Xu et al ., 2018; Hua et al ., 2021). In addition, several genes required for the initiation of trichomes in other vegetables have been identified, such as Ptl1 , the pepper trichome locus 1 in Capsicum annuum , and Brtri1 , a gene controlling trichome development in Chinese cabbage (Kim et al ., 2010; Ye et al ., 2016).…”

Construction of an Intragenic SSR-Based Linkage Map and QTL Mapping for Agronomic Traits in Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

“…Horticulturae 2022, 8, 165 2 of 15 RFLP [4], STS [5], simple sequence repeat (SSR) [6][7][8][9], InDel [7,8], and SNP [2,10,11], in different genetic populations such as F 2 [2,3,6,7,9], F 3 [5], RIL [4,8,10], and DH lines [1,11]. A number of quantitative trait loci (QTLs) have been identified in Chinese cabbage recently, including trichome number [12][13][14], flowering time [11,15], flower color [16], anthocyanin accumulation [17], plant morphological traits [7,15,[18][19][20][21], orange inner leaves [6,22], seed coat color [3,9,23,24], bolting trait [8], floral stalk length [25], disease resistance [5,[26][27][28][29], reproductive...…”

“…A number of quantitative trait loci (QTLs) have been identified in Chinese cabbage recently, including trichome number [12][13][14], flowering time [11,15], flower color [16], anthocyanin accumulation [17], plant morphological traits [7,15,[18][19][20][21], orange inner leaves [6,22], seed coat color [3,9,23,24], bolting trait [8], floral stalk length [25], disease resistance [5,[26][27][28][29], reproductive fitness traits [4], and yield-related traits [1,30]. For some genetically simple traits such as trichome number [12][13][14], seed coat color [3,9,25], and orange inner leaves [6,22,31], many candidate genes have been identified according to map-based cloning methods, and efficient molecular markers have been developed for marker-assisted selection (MAS). However, for plant morphological and yield-related traits, only a handful of candidate genes and efficient molecular markers have been used for MAS [1].…”