%0 Journal Article
%T Interactive effects of α-NAA and UV-B radiation on the endogenous hormone contents and growth of Trichosanthes kirilowii Maxim seedlings
%A Yun Liu
%A Zhang-Cheng Zhong
%J 生态学报
%D 2009
%I 
%X The impact of UV-B radiation on endogenous hormones in plants has recently drawn attention from researchers. The mechanism for reduced stem elongation by UV-B might be due to changes in the phytohormone levels, especially IAA, which plays a role in stem elongation. In this study, effects of UV-B radiation on Trichosanthes kirilowii Maxim (T. kirilowii) seedlings in greenhouse-grown plants were investigated. The results indicated that: (1) In comparison to controls, exposure to 0.029 Jm?2 s?1. UV-B radiation led to accumulation of endogenous abscisic acid (ABA) and zeatinriboside (ZR) in the plant contents, and decreased contents of endogenous indole-3-acetic acid (IAA) and gibberellic acid (GA1/3). Exposure to UV-B radiation reduced the height and leaf area of plants. As a result, total biomass (plant dry weight) was lower. (2) In comparison to controls, addition of 2 mg l?1 α-naphthaleneacetic acid (α-NAA) slightly increased the contents of IAA, GA1/3 and ZR, and decreased the content of ABA in leaves. This addition of α-NAA significantly increased plant height and leaf area, but only slightly increased total biomass. (3) Addition of α-NAA to UV-B-exposed plants: increased the content of endogenous IAA, GA1/3 and ZR; decreased accumulation of endogenous ABA; and increased plant height and leaf area in comparison to plants that only were exposed to UV-B. Moreover, total biomass increased slightly. This suggests that addition of α-NAA may compensate to a certain extent for the lack of IAA resulting from UV-B radiation; it also increases the content of GA1/3 and ZR, decreases the accumulation of ABA, and promotes the growth of plants.
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=FE163E5DB2274E5937319DE98913EC37&aid=0CCC640136EA455C95C5A3410BEEEB28&yid=DE12191FBD62783C&vid=771469D9D58C34FF&iid=E158A972A605785F&sid=5B5B75F4854B8331&eid=FBA00558C57D9C11&journal_id=1000-0933&journal_name=生态学报&referenced_num=0&reference_num=0