AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.
AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.
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DOI：
10.1371/journal.pgen.1005903
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发表时间：
2016-03
期刊：
影响因子：
4.5
通讯作者：
Aharoni A
中科院分区：
文献类型：
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作者：
Breitel DA;Chappell-Maor L;Meir S;Panizel I;Puig CP;Hao Y;Yifhar T;Yasuor H;Zouine M;Bouzayen M;Granell Richart A;Rogachev I;Aharoni A
乙烯在果实成熟过程中的参与是有据可查的，尽管关于乙烯和其他激素在成熟过程中的相互作用的知识还缺乏。我们发现，生长素反应因子2A（ARF 2A），公认的生长素信号成分，在成熟的控制功能。ARF 2A表达在rin、nor和nr成熟突变体中受到成熟调节和降低。它也对外源乙烯、生长素和脱落酸（阿坝）的施加有反应。在番茄中过量表达ARF 2A导致斑点成熟，其中某些果实区域变红并具有加速成熟。过表达ARF 2A的果实表现出早期乙烯释放，乙烯信号抑制延迟其成熟表型，表明乙烯依赖性。绿色和红色果实区域都显示出乙烯信号组分的诱导和成熟的主调节剂。全面的激素分析表明，改变ARF 2A在水果中的表达显着修改的横坐标，细胞分裂素和水杨酸，而赤霉酸和生长素代谢产物不受影响。ARF 2A的沉默进一步验证了这些观察结果，因为降低ARF 2A表达会延迟果实成熟，单性结实和干扰激素谱。最后，我们表明，ARF 2A均homodimerizes和相互作用的阿坝应力催熟（ASR 1）蛋白，表明ASR 1可能是连接阿坝和乙烯依赖的成熟。这些结果表明，ARF 2A互连乙烯和其他激素的信号，以协调果实组织的能力，启动复杂的成熟过程。已知乙烯激素参与肉质果实成熟，尽管其他激素的作用研究较少。本文研究了生长素反应因子2A（ARF 2A）在番茄果实成熟过程中的作用，并认为它可能参与乙烯与其他激素之间的相互作用。我们发现，ARF 2A（ARF 2-OX）的过度表达导致果实以不均匀，斑点的方式成熟。ARF 2-OX果实的成熟时间受外源乙烯的影响，但成熟区域的杂色外观与乙烯无关。与ARF 2-OX果实中的发现一致，ARF 2旁系同源物ARF 2A和ARF 2B（ARF 2as）的沉默延迟了成熟过程。全面的激素分析表明，在水果中的ARF 2表达的改变显着影响横坐标，细胞分裂素和水杨酸，而赤霉酸和生长素代谢产物不受影响。对ARF 2-OX果实斑块的转录组分析显示，正常成熟确实发生，但是，时机和协调受到影响。这些观察结果在显示相反基因表达和代谢表型的ARF 2as果实中得到加强。最后，我们表明，ARF 2A同源二聚体，以及与已知的阿坝应力成熟（ASR 1）蛋白相互作用，这表明ASR 1可能是连接阿坝和乙烯依赖性成熟。我们的研究结果表明，ARF 2A可能互连乙烯和其他激素的信号，协调果实组织的能力，启动复杂的成熟过程。
The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process. The hormone ethylene is known to be involved in fleshy fruit ripening, although the role of other hormones is less well studied. Here we investigated the role of AUXIN RESPONSE FACTOR 2A (ARF2A) in tomato fruit ripening and suggest that it may be involved in the crosstalk between ethylene and other hormones. We show that over-expression of ARF2A (ARF2-OX) causes the fruit to ripen in an uneven, blotchy manner. The timing of ripening in ARF2-OX fruit is affected by applying exogenous ethylene, but the variegated appearance of ripening regions is independent of ethylene. In agreement with findings in ARF2-OX fruit, silencing of both ARF2 paralogs, ARF2A and ARF2B (ARF2as), delayed the ripening process. Comprehensive hormone profiling revealed that altered ARF2 expression in fruit significantly impacted abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Transcriptome analysis of ARF2-OX fruit patches revealed that normal ripening does occur, however, the timing and co-ordination is affected. These observations were reinforced in ARF2as fruit that displayed the opposite gene expression and metabolic phenotypes. Finally, we show that ARF2A homodimerizes as well as interacts with the known ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. Our results reveal that ARF2A may interconnect signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process.