Multi-omics Analysis Reveals Sequential Roles for ABA during Seed Maturation
Multi-omics Analysis Reveals Sequential Roles for ABA during Seed Maturation
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DOI：
10.1104/pp.19.00338
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发表时间：
2019-06-01
期刊：
影响因子：
7.4
通讯作者：
Marion-Poll, Annie
中科院分区：
文献类型：
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作者：
Chauffour, Frederic;Bailly, Marlene;Marion-Poll, Annie
脱落酸（阿坝）是种子发育和萌发的重要激素，其生理作用受内源ABA水平的调节。9-顺式环氧类胡萝卜素双加氧酶（NCED）对类胡萝卜素前体的裂解和阿坝8 ′-羟化酶（CYP 707 A）对阿坝的失活是关键的代谢调控步骤。在拟南芥（Arabidopsis thaliana）中，这两种酶都由多基因家族编码，具有独特的表达模式。为了评估全基因组范围内的影响，阿坝缺乏在发育中的种子在成熟阶段时，休眠诱导，我们使用了nced 2569四重突变体，其中阿坝缺乏主要限于种子，从而限制了种子生理的影响，母体缺陷。nced 2569种子中阿坝含量很低，与严重突变体aba 2相似;出乎意料的是，在aba 2种子中检测到阿坝Glc酯，表明存在替代代谢途径。与nced 259和野生型相比，nced 2569种子中的激素含量强烈表明，NCED 6在胚乳中的特异表达主要负责阿坝的产生。因此，转录组分析揭示了nced 2569与野生型或nced 259发育中种子之间基因表达的广泛相似性。基因本体丰富揭示了大范围的阿坝激活靶点，涉及储备存储和脱水耐受性，以及光合作用和细胞周期的抑制。与野生型和cyp 707 a1 a2种子相比，干燥nced 2569种子的蛋白质组和代谢组特征也突出了阿坝对储备再动员、活性氧产生和蛋白质氧化的抑制作用。阿坝对这些氧化过程的下调可能在休眠控制中起重要作用。
Abscisic acid (ABA) is an important hormone for seed development and germination whose physiological action is modulated by its endogenous levels. Cleavage of carotenoid precursors by 9-cis epoxycarotenoid dioxygenase (NCED) and inactivation of ABA by ABA 8'-hydroxylase (CYP707A) are key regulatory metabolic steps. In Arabidopsis (Arabidopsis thaliana), both enzymes are encoded by multigene families, having distinctive expression patterns. To evaluate the genome-wide impact of ABA deficiency in developing seeds at the maturation stage when dormancy is induced, we used a nced2569 quadruple mutant in which ABA deficiency is mostly restricted to seeds, thus limiting the impact of maternal defects on seed physiology. ABA content was very low in nced2569 seeds, similar to the severe mutant aba2; unexpectedly, ABA Glc ester was detected in aba2 seeds, suggesting the existence of an alternative metabolic route. Hormone content in nced2569 seeds compared with nced259 and wild type strongly suggested that specific expression of NCED6 in the endosperm is mainly responsible for ABA production. In accordance, transcriptome analyses revealed broad similarities in gene expression between nced2569 and either wild-type or nced259 developing seeds. Gene ontology enrichments revealed a large spectrum of ABA activation targets involved in reserve storage and desiccation tolerance, and repression of photosynthesis and cell cycle. Proteome and metabolome profiles in dry nced2569 seeds, compared with wild-type and cyp707a1a2 seeds, also highlighted an inhibitory role of ABA on remobilization of reserves, reactive oxygen species production, and protein oxidation. Down-regulation of these oxidative processes by ABA may have an essential role in dormancy control.