Chen Xia, Zhang Min, Tan Jie, Huang Shuping, Wang Chunli, Zhang Hongyuan, Tan Taiming
Wuhan Vegetable Research Institute, Wuhan Academy of Agricultural Science and Technology, Wuhan, Hubei, China.
PLoS One. 2017 Jun 12;12(6):e0179491. doi: 10.1371/journal.pone.0179491. eCollection 2017.
Genetic control of parthenocarpy, a desirable trait in edible fruit with hard seeds, has been extensively studied. However, the molecular mechanism of parthenocarpic fruit development in eggplant (Solanum melongena L.) is still unclear. To provide insights into eggplant parthenocarpy, the transcriptomic profiles of a natural parthenocarpic (PP05) and two non-parthenocarpic (PnP05 and GnP05) eggplant lines were analyzed using RNA-sequencing (RNA-seq) technology. These sequences were assembled into 38925 unigenes, of which 22683 had an annotated function and 3419 were predicted as novel genes or from alternative splicing. 4864 and 1592 unigenes that were identified as DEGs between comparison groups PP05 vs PnP05 and PP05 vs GnP05, respectively. 506 common DEGs were found contained in both comparison groups, including 258 up-regulated and 248 down-regulated genes. Functional enrichment analyses identified many common or specific biological processes and gene set potentially associated with plant development. The most pronounced findings are that differentially regulated genes potentially-related with auxin signaling between parthenocarpic and non-parthenocarpic eggplants, e.g. calcium-binding protein PBP1 and transcription factor E2FB, which mediate the auxin distribution and auxin-dependent cell division, respectively, are up-regulated in the PP05; whereas homologs of GH3.1 and AUX/IAA, which are involved in inactivation of IAA and interference of auxin signaling, respectively, are down-regulated in PP05. Furthermore, gibberellin and cytokinin signaling genes and genes related to flower development were found differentially regulated between these eggplant lines. The present study provides comprehensive transcriptomic profiles of eggplants with or without parthenocarpic capacity. The information will deepen our understanding of the molecular mechanisms of eggplant parthenocarpy. The DEGs, especially these filtered from PP05 vs PnP05 + GnP05, will be valuable for further investigation of key genes involved in the parthenocarpic fruit development and genomics-assisted breeding.
单性结实是硬籽食用果实中一种理想的性状，其遗传控制已得到广泛研究。然而，茄子（Solanum melongena L.）单性结实果实发育的分子机制仍不清楚。为了深入了解茄子的单性结实，利用RNA测序（RNA-seq）技术分析了一个天然单性结实（PP05）和两个非单性结实（PnP05和GnP05）茄子品系的转录组图谱。这些序列被组装成38925个单基因，其中22683个具有注释功能，3419个被预测为新基因或来自可变剪接。分别在比较组PP05与PnP05和PP05与GnP05之间鉴定出4864个和1592个差异表达基因（DEG）。在两个比较组中发现了506个共同的DEG，包括258个上调基因和248个下调基因。功能富集分析确定了许多与植物发育潜在相关的共同或特定生物学过程和基因集。最显著的发现是，在单性结实和非单性结实茄子之间，与生长素信号传导潜在相关的差异调节基因，例如分别介导生长素分布和生长素依赖性细胞分裂的钙结合蛋白PBP1和转录因子E2FB，在PP05中上调；而分别参与IAA失活和生长素信号传导干扰的GH3.1和AUX/IAA的同源物在PP05中下调。此外，发现赤霉素和细胞分裂素信号基因以及与花发育相关的基因在这些茄子品系之间存在差异调节。本研究提供了具有或不具有单性结实能力的茄子的综合转录组图谱。这些信息将加深我们对茄子单性结实分子机制的理解。这些DEG，特别是从PP05与PnP05 + GnP05中筛选出的DEG，对于进一步研究参与单性结实果实发育的关键基因和基因组辅助育种将具有重要价值。
