Exogenous spermine pretreatment confers tolerance to combined high-temperature and drought stress in vitro in trifoliate orange seedlings via modulation of antioxidative capacity and expression of stress-related genes
Exogenous spermine pretreatment confers tolerance to combined high-temperature and drought stress in vitro in trifoliate orange seedlings via modulation of antioxidative capacity and expression of stress-related genes
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DOI：
10.1080/13102818.2014.909152
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发表时间：
2014-01-01
影响因子：
1.4
通讯作者：
Jiang, Cai-Lun
中科院分区：
文献类型：
--
作者：
Fu, Xing-Zheng;Xing, Fei;Jiang, Cai-Lun
精胺（Spm）被认为在干旱或高温（HT）耐受性中起重要作用。然而，目前尚不清楚是否Spm赋予类似的电阻在干旱和HT的存在下，这往往同时发生。本研究以橙子（Poncirus trifoliata（L.）拉夫。）用1 mmol L-1 Spm预处理幼苗以评价它们对干旱和HT（45 ℃）组合胁迫的耐受性。在处理的180 min内，经Spm处理的幼苗叶片萎蔫、失水和电解质渗漏量均低于对照叶片。二氨基联苯胺和硝基四氮唑蓝的组织化学染色显示，SPM预处理的幼苗积累的过氧化氢和超氧化物比对照植物60，120和180分钟后处理时，暴露于干旱和HT（45 ℃）。而Spm预处理幼苗的超氧化物歧化酶、过氧化物酶和过氧化氢酶活性均显著高于对照幼苗。此外，Spm预处理的幼苗表现出显着更高的表达热休克蛋白，脱落酸（阿坝）响应元件结合因子和9-顺式环氧类胡萝卜素双加氧酶3比对照前（0分钟）或后（60，120和180分钟）干旱和高温处理相结合。所有这些数据表明，外源Spm预处理赋予同时发生的干旱和HT胁迫的耐受性。Spm可能通过激活抗氧化酶，增加清除活性氧的有效性来影响这一点。它也可能增加胁迫相关基因的表达水平，保护三叶橙子幼苗免受胁迫伤害。
Spermine (Spm) is thought to play an important role in drought or high-temperature (HT) tolerance. However, it is not clear whether Spm confers similar resistance in the presence of both drought and HT, which often occur simultaneously. In the present study, the trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings were pretreated with 1 mmol L-1 Spm to evaluate their tolerance to combined drought and HT (45 degrees C) stress. Spm-pretreated seedlings showed less leaf wilting, less water loss and less electrolyte leakage than control leaves not treated with Spm within 180 min of treatment. Histochemical staining with diaminobenzidine and nitro blue tetrazolium showed that Spm-pretreated seedlings accumulated less hydrogen peroxide and superoxide than those of control plants 60, 120 and 180 min after treatment when exposed to both drought and HT (45 degrees C). However, superoxide dismutase, peroxidase and catalase were significantly more active in Spm-pretreated seedlings than in control seedlings. In addition, Spm-pretreated seedlings showed significantly higher expression of heat shock proteins, abscisic acid (ABA)-responsive element binding factor and 9-cis-epoxycarotenoid dioxygenase 3 than controls either before (0 min) or after (60, 120 and 180 min) combined drought and HT treatment. All of these data suggest that exogenous Spm pretreatment confers tolerance to simultaneously occurring drought and HT stresses. Spm may influence this by activating antioxidant enzymes, increasing the effectiveness of scavenging of reactive oxygen species. It may also increase the expression levels of stress-related genes that protect trifoliate orange seedlings from stress damage.