Page 93 - 《广西植物》2023年第11期
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11 期 田怀志等: 水涝胁迫下辣椒转录组特征分析及 EST ̄SSR 标记开发 2 0 5 3
Abstract: SSR molecular markers were obtained based on abundant transcriptome data under different waterlogging
conditions in order to develop appropriate biological tools and explore the molecular mechanism of hot pepper response to
waterlogging stress in this experiment. The results were as follows: (1) A total of 128 939 Unigenes were obtained from
transcriptome analysis of hot pepper. The total lengthꎬ average lengthꎬ and GC content were 55 082 725 bpꎬ 1 101 bp
and 40.57%ꎬ respectively. Compared with seven major functional databasesꎬ 102 123 (NRꎬ 79.20%)ꎬ 110 157 (NTꎬ
85.43%)ꎬ 70 203 ( SwissProtꎬ 54.45%)ꎬ 73 539 ( KOGꎬ 57.03%)ꎬ 77 646 ( KEGGꎬ 60.22%)ꎬ 77 442 ( GOꎬ
60.06%) and 68 216 (Pfamꎬ 52.91%) Unigenes obtained functional annotations. It was found that lipid metabolismꎬ
carbohydrate metabolismꎬ amino acid metabolismꎬ environmental adaptationꎬ secondary metabolite biosynthesisꎬ signal
transduction and translation played important roles in the response to waterlogging stress. (2) A total of 26 574 SSR loci
were found in 24 889 Unigenes from hot pepper transcriptome data. The frequency of SSR was 20.61%ꎬ of which single
nucleotide repeat accounted for the highest ratio (37.26%)ꎬ followed by tri ̄nucleotide (31.00%) and di ̄nucleotide
(25.44%) repeat typesꎬ accounting for 93.70% of the total EST ̄SSR. The motifs A/ Tꎬ AG/ CT and TC/ GAꎬ followed
by AT and TAꎬ were the most abundant in mono ̄nucleotide and di ̄nucleotide. The most common types of tri ̄nucleotides
were TTG/ CAA and ACA/ TGT. (3) 10 002 pairs of EST ̄SSR primers were designed with Primer 3. A total of 30 pairs
of primers were randomly selected for amplification testꎬ and all of them were effective. Seven pairs of primers could
amplify the target bands in three hot pepper germplasms. To sum upꎬ the motif structure of the most dominant SSR repeat
type in hot pepper is basically similar to that of other varietiesꎬ and the molecular mechanism of hot pepper waterlogging
stress response is preliminarily exploredꎬ and its EST ̄SSR markers are developed to provide reference for hot pepper
waterlogging ̄tolerant genetic breeding.
Key words: Capsicum annuum (hot pepper)ꎬ waterlogging stressꎬ response mechanismꎬ transcriptomeꎬ EST ̄SSR
辣椒(Capsicum annuum)作为世界上第二大茄 发均具有重要意义ꎬ是探究植物耐涝分子机制的
科蔬菜ꎬ是我国种植面积最大的蔬菜( 邹学校等ꎬ 有力工具ꎮ Kinga 等(2021) 对两个耐涝性不同的
2020)ꎮ 伴随着辣椒用途的不断开发和加工型产 黄瓜品种进行转录组分析ꎬ发现在耐涝品种中所
业的快速发展ꎬ其已成为我国乡村振兴的重要支 鉴定的基因与增强糖酵解、氨基酸代谢和不定根
柱产业之一ꎮ 但是ꎬ辣椒属于浅根系作物ꎬ根系不 发育相关ꎮ Xu 等(2017)对黄瓜转录组进行分析ꎬ
发达ꎬ再生能力弱ꎬ耐涝能力差ꎮ 长江中下游地区 发现耐涝植株表现出更高的碳水化合物代谢以及
涝害频繁发生ꎬ导致辣椒减产减收严重( 刘周斌 三磷酸腺苷和还原型辅酶Ⅰ的再生ꎬ以应对水涝
等ꎬ2015)ꎮ 目前ꎬ对辣椒耐涝胁迫方面的研究较 胁迫带来的能量危机ꎮ Pimprapai 等( 2011) 研究
少且主要集中于生理方面ꎬ对其分子机理的研究 了两个不同耐涝性豌豆品种的分子响应变化ꎬ通
更少ꎮ 耐涝是受多基因控制的性状ꎬ难以定位ꎬ仅 过对根的转录组研究ꎬ发现能量代谢通路、激素、
基于表型很难快速地将这些性状加以利用ꎮ 利用 细胞壁修饰、膜转运蛋白和过氧化物酶相关的多
分子标记进行预选可减少群体规模ꎬ并可在辣椒 个差异表达基因可能有助于豌豆的耐涝ꎮ Li 等
生长早期筛选出理想的基因型ꎬ可加速辣椒新品 (2022)通过转录组分析发现耐涝猕猴桃根系通过
种培育进程ꎮ 调节碳水化合物和氨基酸代谢来应对水涝胁迫ꎮ
转录组测序( RNA ̄seq) 技术利用高通量测序 另外ꎬ叶鹏等(2019) 通过对金花茶转录组数据的
进行基因表达水平分析ꎬ可以反映基因的转录水 挖掘ꎬ获得 SSR 位点分布特征ꎬ为 SSR 引物设计与
平ꎬ能快速有效地获得基因序列ꎮ 其因高通量、准 筛选提供依据ꎮ
确性和可重复性等优点ꎬ现已被广泛应用到分子 SSR 因其具有丰富的数量、较高的多态性、良
生物学领域ꎮ RNA ̄seq 技术加速了新基因表达模 好的重复性以及共显性等优点而被广泛应用( 罗
式和功能的分析( Jain et al.ꎬ 2016)ꎬ是分析生物 冉等ꎬ2010)ꎬ但 SSR 标记的开发需要经过构建文
体 基 因 表 达 量 变 化 的 重 要 工 具 ( Zhang et al.ꎬ 库、筛选和测序等工作ꎬ既昂贵又繁琐ꎮ 如今ꎬ大
2017)ꎬ其对非模式植物的基因挖掘和分子标记开 规模开展的 cDNA 测序工作以及飞速发展的生物