Table_5_Investigation of Thermomorphogenesis-Related Genes for a Multi-Silique Trait in Brassica napus by Comparative Transcriptome Analysis.DOCX

In higher plants, the structure of a flower is precisely controlled by a series of genes. An aberrance flower results in abnormal fruit morphology. Previously, we reported multi-silique rapeseed (Brassica napus) line zws-ms. We identified two associated regions and investigated differentially expressed genes (DEGs); thus, some candidate genes underlying the multi-silique phenotype in warm area Xindu were selected. However, this phenotype was switched off by lower temperature, and the responsive genes, known as thermomorphogenesis-related genes, remained elusive. So, based on that, in this study, we further investigated the transcriptome data from buds of zws-ms and its near-isogenic line zws-217 grown in colder area Ma’erkang, where both lines showed normal siliques only, and the DEGs between them analyzed. We compared the 129 DEGs from Xindu to the 117 ones from Ma’erkang and found that 33 of them represented the same or similar expression trends, whereas the other 96 DEGs showed different expression trends, which were defined as environment-specific. Furthermore, we combined this with the gene annotations and ortholog information and then selected BnaA09g45320D (chaperonin gene CPN10-homologous) and BnaC08g41780D [Seryl-tRNA synthetase gene OVULE ABORTION 7 (OVA7)-homologous] the possible thermomorphogenesis-related genes, which probably switched off the multi-silique under lower temperature. This study paves a way to a new perspective into flower/fruit development in Brassica plants.

高等植物中，花的结构受一系列基因的精准调控。花发育异常会导致果实形态畸形。此前本团队已报道过多角果甘蓝型油菜（Brassica napus）品系zws-ms。本研究团队此前鉴定到两个关联区域，并对差异表达基因（differentially expressed genes, DEGs）进行了分析，由此筛选出了在温暖地区新都（Xindu）中调控多角果表型的候选基因。然而该表型可被低温抑制，而其中的温度响应相关基因（即热形态建成相关基因，thermomorphogenesis-related genes）仍未被阐明。基于此，本研究进一步对种植于寒冷地区马尔康（Ma’erkang）的zws-ms及其近等基因系zws-217的芽组织转录组数据进行了分析，两个品系在该地区仅能形成正常角果；同时对二者间的差异表达基因进行了分析。本研究将来自新都的129个差异表达基因与来自马尔康的117个差异表达基因进行对比，发现其中33个基因的表达趋势相同或相似，剩余96个基因的表达趋势存在显著差异，此类基因被定义为环境特异性基因。此外，结合基因注释信息与同源基因分析结果，本研究筛选得到两个潜在的热形态建成相关基因：BnaA09g45320D（伴侣蛋白基因CPN10同源基因）与BnaC08g41780D【丝氨酰-tRNA合成酶基因OVULE ABORTION 7（OVA7）同源基因】，它们可能在低温条件下抑制多角果表型的形成。本研究为芸苔属植物的花/果实发育研究开辟了全新的视角。