Wang Xiaoyan, Zhang Xuemei, Zhao Lei, Guo Zhenhua
China Southwest Germplasm Bank of Wild Species, the Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
Int J Mol Sci. 2014 Jul 7;15(7):12074-93. doi: 10.3390/ijms150712074.
The mechanism of floral transition in bamboo remains unclear. Dendrocalamus latiflorus (Bambusease, Bambusoideae, Poaceae) is an economically and ecologically important clumping bamboo in tropical and subtropical areas. We evaluated morphological characteristics and gene expression profiling to study floral induction and early flower development in D. latiflorus. The detailed morphological studies on vegetative buds and floral organography were completed using paraffin sectioning and scanning electron microscopy. The 3 mm floral buds commence the development of stamen primordia and pistil primordium. Furthermore, homologs of floral transition-related genes, including AP1, TFL1, RFL, PpMADS1, PpMADS2, SPL9, FT, ID1, FCA, and EMF2, were detected and quantified by reverse transcriptase PCR and real-time PCR in vegetative and floral buds, respectively. Distinct expression profiles of ten putative floral initiation homologues that corresponded to the developmental stages defined by bud length were obtained and genes were characterized. Six of the genes (including DlTFL1, DlRFL, DlMADS2, DlID1, DlFCA, DlEMF2) showed statistically significant changes in expression during floral transition. DlAP1 demonstrated a sustained downward trend and could serve as a good molecular marker during floral transition in D. latiflorus. The combined analysis provided key candidate markers to track the transition from the vegetative to reproductive phase.
竹子开花转变的机制尚不清楚。麻竹（禾本科竹亚科竹属）是热带和亚热带地区一种具有重要经济和生态价值的丛生竹。我们评估了形态特征和基因表达谱，以研究麻竹的成花诱导和早期花发育。使用石蜡切片和扫描电子显微镜完成了对营养芽和花器官形态的详细形态学研究。3毫米的花芽开始雄蕊原基和雌蕊原基的发育。此外，通过逆转录PCR和实时PCR分别在营养芽和花芽中检测和定量了与开花转变相关的基因同源物，包括AP1、TFL1、RFL、PpMADS1、PpMADS2、SPL9、FT、ID1、FCA和EMF2。获得了十个假定的成花起始同源物与由芽长度定义的发育阶段相对应的不同表达谱，并对基因进行了表征。其中六个基因（包括DlTFL1、DlRFL、DlMADS2、DlID1、DlFCA、DlEMF2）在开花转变期间表现出统计学上显著的表达变化。DlAP1表现出持续下降的趋势，可作为麻竹开花转变过程中的一个良好分子标记。综合分析提供了追踪从营养生长阶段到生殖阶段转变的关键候选标记。
