Control of Abscisic Acid Catabolism and Abscisic Acid Homeostasis Is Important for Reproductive Stage Stress Tolerance in Cereals
Control of Abscisic Acid Catabolism and Abscisic Acid Homeostasis Is Important for Reproductive Stage Stress Tolerance in Cereals
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DOI：
10.1104/pp.111.176164
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发表时间：
2011-06-01
期刊：
影响因子：
7.4
通讯作者：
Dolferus, Rudy
中科院分区：
文献类型：
--
作者：
Ji, Xuemei;Dong, Baodi;Dolferus, Rudy
生殖阶段的干旱胁迫会导致小麦（Triticum aestivum）花粉不育和籽粒损失。干旱胁迫会诱导对干旱敏感的小麦品种的花药中脱落酸（ABA）生物合成基因和穗中脱落酸的积累。相比之下，耐旱小麦积累的 ABA 水平较低，这与较低的 ABA 生物合成和较高的 ABA 分解代谢基因表达（ABA 8'-羟化酶）相关。小麦 TaABA8'OH1 缺失系积累了更高的穗 ABA 水平并且对干旱更加敏感。 ABA 对穗的处理模拟了干旱的影响，导致高度不育。 ABA 处理抑制花药细胞壁转化酶基因 TaIVR1，耐旱品系似乎对 ABA 的作用更敏感。干旱引起的不育与水稻（Oryza sativa）中寒冷引起的不育相似。在冷胁迫水稻中，冷敏感品系和耐冷品系在冷处理的前8小时内ABA积累率相似，但在耐冷品系中，ABA分解代谢在冷处理8至16小时期间降低了ABA水平。花药中编码9-顺式环氧类胡萝卜素双加氧酶的ABA生物合成基因主要在花药维管束周围的薄壁细胞中表达。在 OsG6B 绒毡层特异性启动子控制下表达小麦 TaABA8'OH1 基因的转基因水稻品系导致寒冷条件下花药 ABA 水平降低。转基因品系表明，在寒冷条件下花药库强度（OsINV4）得以维持，并且这与改善的冷胁迫耐受性相关。我们的数据表明，ABA 和 ABA 8'-羟化酶在控制谷物花药 ABA 稳态和生殖阶段非生物胁迫耐受性中发挥着重要作用。
Drought stress at the reproductive stage causes pollen sterility and grain loss in wheat (Triticum aestivum). Drought stress induces abscisic acid (ABA) biosynthesis genes in anthers and ABA accumulation in spikes of drought-sensitive wheat varieties. In contrast, drought-tolerant wheat accumulates lower ABA levels, which correlates with lower ABA biosynthesis and higher ABA catabolic gene expression (ABA 8'-hydroxylase). Wheat TaABA8'OH1 deletion lines accumulate higher spike ABA levels and are more drought sensitive. ABA treatment of the spike mimics the effect of drought, causing high levels of sterility. ABA treatment represses the anther cell wall invertase gene TaIVR1, and drought-tolerant lines appeared to be more sensitive to the effect of ABA. Drought-induced sterility shows similarity to cold-induced sterility in rice (Oryza sativa). In cold-stressed rice, the rate of ABA accumulation was similar in cold-sensitive and cold-tolerant lines during the first 8 h of cold treatment, but in the tolerant line, ABA catabolism reduced ABA levels between 8 and 16 h of cold treatment. The ABA biosynthesis gene encoding 9-cis-epoxycarotenoid dioxygenase in anthers is mainly expressed in parenchyma cells surrounding the vascular bundle of the anther. Transgenic rice lines expressing the wheat TaABA8'OH1 gene under the control of the OsG6B tapetum-specific promoter resulted in reduced anther ABA levels under cold conditions. The transgenic lines showed that anther sink strength (OsINV4) was maintained under cold conditions and that this correlated with improved cold stress tolerance. Our data indicate that ABA and ABA 8'-hydroxylase play an important role in controlling anther ABA homeostasis and reproductive stage abiotic stress tolerance in cereals.