Classification and characteristics of heat tolerance in Ageratina adenophora populations using fast chlorophyll a fluorescence rise O-J-I-P
Classification and characteristics of heat tolerance in Ageratina adenophora populations using fast chlorophyll a fluorescence rise O-J-I-P
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利用快速叶绿素a荧光上升O-J-I-P对紫茎泽兰种群的耐热性进行分类和特征
DOI：
10.1016/j.envexpbot.2015.09.011
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发表时间：
2016-02-01
影响因子：
5.7
通讯作者：
Qiang, Sheng
中科院分区：
文献类型：
--
作者：
Chen, Shiguo;Yang, Juan;Qiang, Sheng
Croftonweed原产于墨西哥，是一种世界性的入侵杂草。本研究旨在筛选不同紫茎泽兰种群的耐热性，测定热胁迫对紫茎泽兰两个光系统的影响，探讨紫茎泽兰获得耐热性的机制。根据常规的植物伤害和叶绿素荧光快速上升动力学试验，将采自中国南方的4个紫茎泽兰种群进行40 ℃热处理，成功地将其分为敏感型、中间型和耐受型三类。JIP试验结果表明，放氧复合物（OEC）的抑制和PSII反应中心（RC）的失活是造成热损伤的主要原因。在温和的热应力（= 40摄氏度），一个明显的K-步骤，由于不可逆的严重损害的OEC发生。此外，PSII RC失活，PSII单元能量连接下调，PSII天线结构破坏，PSII整体光合活性丧失，PSI活性增加。而且，相对于中间和敏感群体，耐性群体的光合能力受到的伤害程度较小。最后，一个可靠的模型，基于最敏感的参数PIABS和V-K作为热胁迫的特征参数，提出了在不同的紫茎泽兰种群的耐热性排序和鉴定。热敏感性指数（HSI）也被引入作为植物热敏感性的指标。HSI值越小，表明其耐热性越高。研究还发现，4个紫茎泽兰种群对高温胁迫的耐受程度与极端高温显著相关。这表明紫茎泽兰种群获得的耐热性是植物对环境高温适应的结果。耐热性的获得赋予了紫茎泽兰进一步传播到目前较热地区的可能风险。(C)2015 Elsevier B. V.版权所有。
Croftonweed originated from Mexico is a worldwide notorious invasive weed. The objectives of this study were to screen heat tolerance in different croftonweed populations, determine the effect of heat stress on two photosystems and probe the mechanism of acquired heat tolerance. According to conventional tests of plant injury and fast chlorophyll fluorescence rise kinetics, four different croftonweed populations collected from South China were successfully classified into three categories by exposing whole plants to heat treatment at 40 degrees C: sensitive, intermediate, tolerant. Evidence from the JIP-test indicated that inhibition of the oxygen evolution complexes (OEC) and inactivation of PSII reaction centers (RCs) were the primary cause of heat damage. In mild heat stress (= 40 degrees C), a pronounced K-step due to irreversible severe damage on the OEC occurred. Additionally, inactivation of PSII RCs, down-regulation of energetic connectivity of PSII units, destruction of PSII antenna architecture, losing overall photosynthetic activity of PSII, increase of PSI activity also took place. Furthermore, the tolerant population had lesser damage degree on photosynthetic capacity relative to intermediate and sensitive populations. Finally, a reliable model, based on the most sensitive parameter PIABS and V-K as a characteristic parameter for heat stress, is presented for ranking and identifying heat tolerance in different croftonweed populations. The heat sensitivity index (HSI) is also introduced as an indicator of plant heat sensitivity. The smaller the HSI value is, the higher the level of tolerance to heat stress is. We also found that the tolerance degree of four croftonweed populations to heat stress is significantly correlated to the extreme high temperature. This indicates that acquired heat tolerance in croftonweed populations results from plant adaptation to ambient high temperatures. Acquirement of heat tolerance confers a possible risk for croftonweed to spread further to currently hotter areas. (C) 2015 Elsevier B.V. All rights reserved.