中国农业科学 ›› 2011, Vol. 44 ›› Issue (8): 1670-1677 .doi: 10.3864/j.issn.0578-1752.2011.08.016

• 园艺 • 上一篇    下一篇

低温对朵丽蝶兰成花过程中碳水化合物及糖转运蛋白基因表达的影响

张迟1,周庐萍2,罗小燕2,孙小明2,秦巧平2,周明兵2,崔永一1   

  1. 1. 浙江农林大学
    2.
  • 收稿日期:2010-10-11 修回日期:2010-11-29 出版日期:2011-04-15 发布日期:2011-04-15
  • 通讯作者: 张迟

Relative Cold-induced Flowering Arouse Fluctuation on Carbohydrates and Expression of Genes related to Sugar Transport in Doritaenopsis hybrid

  1. 1. 浙江农林大学
    2.
  • Received:2010-10-11 Revised:2010-11-29 Online:2011-04-15 Published:2011-04-15
  • Contact: Chi ZHANG

摘要: [目的]蝴蝶兰(Phalaenopsis)原产热带,其成花过程中的“温敏”现象已成为制约蝴蝶兰产业发展的重要因素。朵丽蝶兰(Doritaenopsis hybrid)是朵丽兰(Doritis)与蝴蝶兰(Phalaenopsis)的杂交后代,是目前商业应用最广泛的蝶兰种类之一。研究其在相对低温诱导下的营养生长特性及相关基因的表达模式,对明确蝶兰花芽分化的生理生化机制,并深入理解蝶兰成花“温敏”现象的机理,推动整个蝴蝶兰产业的发展有着重要的意义。 [方法]本研究对朵丽蝶兰(Doritaenopsis hybrid)进行高温(30℃/25℃)和低温(22℃/18℃)处理,测定其叶片的生长和叶绿素荧光,以及碳水化合物的含量变化,同时对朵丽蝶兰(Doritaenopsis hybrid)‘温敏’SSH文库中分离的两个糖转运蛋白基因(片段)在相对低温处理下的表达特性进行分析, [结果]结果显示,低温处理的整个阶段,蝶兰叶面积的增长显著低于高温处理,并且在低温处理的前四周(28d),叶片的光能转化效率和PSII的活性明显下降,叶片的淀粉含量急剧下降,还原糖含量持续增加,蔗糖含量在第28d前后表现为先增后减,其中,在低温处理21d至35d中,DhST1的mRNA表达与蔗糖含量的变化一致,而DhSUT1则表现为持续的下降,但二者在抽出的花梗中都有较高的表达量。[结论]低温明显诱导朵丽蝶兰叶片营养生长的减缓,并在处理的开始阶段对光合系统产生一定抑制,同时,碳水化合物含量及相关的糖转运蛋白基因对低温表现出明显的响应,但相关基因表达模式的差异说明在低温诱导的花芽形成过程中承担着不同的重要作用,为进一步明确蝴蝶兰成花“温敏”现象的分子机理提供科学依据。

关键词: 朵丽蝶兰, “温敏”现象, 碳水化合物, 叶绿素荧光, 糖转运蛋白

Abstract: [Objective] Cold-induced flowering in Phalaenopsis, originated in tropical region, was the restrictions of commercially production because of their costing waste. Doritaenopsis, a hybridization of Doritis and Phalanopsis, became the most popular potted flowering crops. Experiments were performed to understand the fluctuation of vegetative growth and gene expression response to relative low temperature, and further to describe this unique inflorescence initiation. [Method] A Doritaenopsis hybrid ‘Tinny Tender’( Doritaenopsis Happy smile ×Happy valentine) was incubated in 22℃/18℃(day/night), with 30℃/25℃ as control, to induce the floral transition. Changes of starch, sucrose, reducing sugar, leaf area, ratio of Fv/Fm and Fv/Fo, and mRNA transcripts levels of 2 genes, annotated as DhSUT1 (Sucrose Transporter) and DhST1 (Sugar Transporter), isolated from the suppression subtractive hybridization (SSH) library of ‘Tinny Tender’. [Result] Slower increasing of leaf area and reducing of Fv/Fm and Fv/Fo were observed under 22℃/18℃ for 28d. Quick degradation of starch, continuous accumulation of reducing sugar and increase to peak at 28d cold-incubation then decrease of sucrose were determined. The mRNA transcripts of DhST1 rose up to the peak at 28d cold-induced, while those of DhSUT1 were decreased. [Conclusion] These results indicated that during cold-induced floral initiation, vegetative growth and photosynthesis capacity of were slow down, and sharp changes in carbohydrates were consist with up-regulated of DhST1 and down-regulated of DhSUT1 expression. In addition, sugar transporter genes performed differently under cold-induced, suggesting those candidate genes were responsible for the unique flowering induction of Doritaenopsis .

Key words: orchid (Doritaenopsis hybrid), ‘cold-sensitive’, carbohydrates, chlorophyll fluorescence, sugar transporter