洪继旺　陈星星　李松刚　张蕾　杨子琴

摘 要 为阐明H2O2和NO对龙眼成花及FT基因表达的影响，选用9年生‘石硖反季节龙眼，结合H2O2和NO促进剂及信号阻断剂喷施，分析龙眼成花及FT基因表达量的动态变化。结果表明：反季节龙眼FT基因表达量在成花过程中上升，且叶片中FT基因表达高峰时间早于顶芽，而SNP和MV均不同程度上调了FT基因的表达；DMTU和L-NNA有效地抑制了顶芽中FT基因的表达，但对花芽分化后期的叶片中FT基因表达抑制不明显。结合龙眼成花情况，推断H2O2和NO信号在促进龙眼成花方面具有重要作用。

关键词 龙眼；成花；H2O2；NO；FT基因

中图分类号 S667.1 文献标识码 A

Abstract This paper focused on the impact of H2O2 and NO on the expression of FT gene and floral bud formation. We sprayed H2O2/NO generators and signal scavenger to the 9-year-old off-season‘Shixia（a variety of Longan）. The measured parameters includes the cases of floral buds and the dynamic changes of the FT gene expression in the leaves and buds. The results showed that the expression quantity of FT gene of off-season Longan rose up in the process of flowering and the peak period of the expression of the FT gene in leaves was earlier than that in terminal buds. The SNP and MV both increased the expression of FT gene in different degrees. The expression of FT gene in terminal buds inhibited effectively by DMTU and L-NNA，but it was not effectively enough when FT gene expressed in the later period of differentiation of flower buds in leaves. Combined with the formation of flowers in Longan，we believe that H2O2 and NO play an important role in promoting the formation of flowers in Longan.

Key words Longan；Flower bud formation；Hydrogen peroxide（H2O2）；Nitric oxide（NO）；FT gene

doi 10.3969/j.issn.1000-2561.2015.11.013

龍眼（Dimocarpus longan Loureiro）是典型的亚热带常绿果树，在中国海南、广东、广西、福建等省区广泛种植。龙眼的成花受低温诱导，而强氧化剂氯酸钾可取代低温诱导龙眼反季节成花，这使得经典的花芽分化理论面临新的挑战。氯酸钾的施用势必造成胁迫，氧化胁迫与低温诱导应存在某些共同之处，从而启动了龙眼花芽分化的发生。由此可见，胁迫诱导的生理信号与成花存在一定的相关性。实际上，低温胁迫以及氧化胁迫存在着共同的特征，即都会导致活性氧和活性氮的累积使植物处于胁迫状态[1-2]。

作为比较稳定的一种活性氧信号分子，H2O2调控许多生理过程，包括产生系统抗性、诱导气孔关闭、诱发过敏性反应[3]。Lokhande等[4]发现，拟南芥开花前的抗坏血酸过氧化物酶活性越高，则开花越迟；氧化胁迫越强，开花越早。为此，Lokhande等[4]提出H2O2是诱导开花的一个因子。……