Advanced Biotechnology and Breeding Centre, Malaysian Palm Oil Board, 6 Persiaran Institusi, 43000, Kajang, Selangor, Malaysia.
Molecular Pathology Unit, Cancer Research Centre (CaRC), Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia.
Plant Reprod. 2019 Jun;32(2):167-179. doi: 10.1007/s00497-018-0350-5. Epub 2018 Nov 22.
Transcriptomes generated by laser capture microdissected abnormal staminodes revealed adoption of carpel programming during organ initiation with decreased expression of numerousHSPs,EgDEF1, EgGLO1but increasedLEAFYexpression. The abnormal mantled phenotype in oil palm involves a feminization of the male staminodes into pseudocarpels in pistillate inflorescences. Previous studies on oil palm flowering utilized entire inflorescences or spikelets, which comprised not only the male and female floral organs, but the surrounding tissues as well. Laser capture microdissection coupled with RNA sequencing was conducted to investigate the specific transcriptomes of male and female floral organs from normal and mantled female inflorescences. A higher number of differentially expressed genes (DEGs) were identified in abnormal versus normal male organs compared with abnormal versus normal female organs. In addition, the abnormal male organ transcriptome closely mimics the transcriptome of abnormal female organ. While the transcriptome of abnormal female organ was relatively similar to the normal female organ, a substantial amount of female DEGs encode HEAT SHOCK PROTEIN genes (HSPs). A similar high amount (20%) of male DEGs encode HSPs as well. As these genes exhibited decreased expression in abnormal floral organs, mantled floral organ development may be associated with lower stress indicators. Stamen identity genes EgDEF1 and EgGLO1 were the main floral regulatory genes with decreased expression in abnormal male organs or pseudocarpel initials. Expression of several floral transcription factors was elevated in pseudocarpel initials, notably LEAFY, FIL and DL orthologs, substantiating the carpel specification programming of abnormal staminodes. Specific transcriptomes thus obtained through this approach revealed a host of differentially regulated genes in pseudocarpel initials compared to normal male staminodes.
通过激光捕获显微解剖异常雄蕊转录组分析发现，在器官起始时采用了心皮编程，导致大量 HSPs、EgDEF1、EgGLO1 表达下调，而 LEAFY 表达上调。油棕异常披叶表型涉及雄性雄蕊在雌性花序中雄性化成为假心皮。先前关于油棕开花的研究利用了整个花序或小穗，其中不仅包含雄性和雌性花器官，还包含周围组织。进行了激光捕获显微解剖与 RNA 测序相结合的研究，以研究正常和披叶雌性花序中雄性和雌性花器官的特定转录组。与异常雌性器官相比，异常雄性器官中差异表达基因 (DEGs) 的数量更多。此外，异常雄性器官转录组与异常雌性器官转录组非常相似。虽然异常雌性器官转录组与正常雌性器官相对相似，但大量雌性 DEGs 编码热休克蛋白基因 (HSPs)。大量雄性 DEGs （约 20%）也编码 HSPs。由于这些基因在异常花器官中的表达降低，披叶花器官发育可能与较低的应激指标有关。雄蕊身份基因 EgDEF1 和 EgGLO1 是主要的花调控基因，在异常雄性器官或假心皮原基中表达下调。几个花转录因子的表达在假心皮原基中上调，特别是 LEAFY、FIL 和 DL 同源物，证实了异常雄蕊的心皮特化编程。通过这种方法获得的特定转录组与正常雄性雄蕊相比，在假心皮原基中揭示了大量差异调控基因。
