Transcriptional and phytohormone regulatory network involved in LITTLELEAF-mediated organ size development in cucumber (Cucumis sativus)
Transcriptional and phytohormone regulatory network involved in LITTLELEAF-mediated organ size development in cucumber (Cucumis sativus)
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DOI：
10.1016/j.scienta.2023.112294
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发表时间：
2023-06-27
影响因子：
4.3
通讯作者：
Yang，Luming
中科院分区：
文献类型：
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作者：
Xu，Nana;Fang，Xiaoxia;Yang，Luming
器官大小，特别是果实大小，是许多园艺作物如黄瓜（Cucumis sativusL.）影响果实产量和品质。器官大小的决定是转录调节因子、植物激素和环境等多种因素复杂相互作用的结果。黄瓜小叶（II）突变表现出小的器官大小，其编码含有缺陷性WD 40重复结构域的蛋白，但LL依赖性器官大小控制的调节机制在很大程度上是未知的。为了检测该基因在不同遗传背景下的功能，探讨其调控网络，我们利用分子标记辅助选择（MAS）技术，将该隐性等位基因导入中国龙自交系9930，构建了该基因的近等基因系（NIL）。通过前景选择和背景选择，在BC_2F_2代培育出了一个近等基因系（HAIL），它与轮回亲本的遗传背景同源，并捕获了轮回亲本遗传背景的96%以上。近等基因系之间的比较形态学分析表明，减少器官大小的突变等位基因是独立的遗传背景。在两个近等基因系的未授粉子房中使用RNA-Seq的转录组分析鉴定了差异表达的基因，这些基因高度富集了已知调节器官大小的基因以及转录因子和各种植物激素生物合成/信号传导途径中的基因。RNA-Seq和植物激素分析发现，生长素和细胞分裂素在LL调控果实生长中发挥更重要的作用。这些结果将有助于进一步探讨黄瓜器官大小的分子机制。
Organ size, especially fruit size, is an economically important trait in many horticulture crops like cucumber (Cucumis sativusL.) which affects both fruit yield and quality. Organ size determination is the outcome of complex interplay of many factors such as transcription regulators, phytohormone and the environments. The cucumberlittleleaf(ll) mutation exhibits small organ size, which encodes a defective WD40 repeat domain-containing protein, but the regulatory mechanisms ofLL-dependent organ size control are largely unknown. To test the functions of thellgene in different genetic backgrounds and explore its regulatory network, we developed near isogenic lines (NIL) ofllgene by introgressing the recessive allele into a Chinese Long inbred line 9930 with marker assisted selection (MAS). Both foreground and background selections were practiced which allowed development of a NIL (HAULL) at BC2F2which were homologous at thelllocus and captured >96% genetic background of the recurrent parent. Comparative morphological analysis between the NILs indicated that the mutant allele for reduced organ size was independent of the genetic background. Transcriptome profiling using RNA-Seq in the unpollinated ovaries of the two NILs identified differentially expressed genes which were highly enriched with genes known to regulate organ size, as well as transcription factors, and genes in various phytohormone biosynthesis/signaling pathways. RNA-Seq and phytohormone assays found that auxin and cytokinin played more important roles inLL-regulated fruit growth. These results will be helpful for further explore the molecular mechanism of organ size in cucumber.