Neves Mariana, Correia Sandra, Cavaleiro Carlos, Canhoto Jorge
Center for Functional Ecology, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal.
CIEPQPF, Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal.
Plants (Basel). 2021 Jun 14;10(6):1208. doi: 10.3390/plants10061208.
Ethylene is a plant hormone controlling physiological and developmental processes such as fruit maturation, hairy root formation, and leaf abscission. Its effect on regeneration systems, such as organogenesis and somatic embryogenesis (SE), has been studied, and progress in molecular biology techniques have contributed to unveiling the mechanisms behind its effects. The influence of ethylene on regeneration should not be overlooked. This compound affects regeneration differently, depending on the species, genotype, and explant. In some species, ethylene seems to revert recalcitrance in genotypes with low regeneration capacity. However, its effect is not additive, since in genotypes with high regeneration capacity this ability decreases in the presence of ethylene precursors, suggesting that regeneration is modulated by ethylene. Several lines of evidence have shown that the role of ethylene in regeneration is markedly connected to biotic and abiotic stresses as well as to hormonal-crosstalk, in particular with key regeneration hormones and growth regulators of the auxin and cytokinin families. Transcriptional factors of the ethylene response factor (ERF) family are regulated by ethylene and strongly connected to SE induction. Thus, an evident connection between ethylene, stress responses, and regeneration capacity is markedly established. In this review the effect of ethylene and the way it interacts with other players during organogenesis and somatic embryogenesis is discussed. Further studies on the regulation of ERF gene expression induced by ethylene during regeneration can contribute to new insights on the exact role of ethylene in these processes. A possible role in epigenetic modifications should be considered, since some ethylene signaling components are directly related to histone acetylation.
乙烯是一种植物激素，可控制果实成熟、毛状根形成和叶片脱落等生理和发育过程。人们已经研究了它对再生系统（如器官发生和体细胞胚胎发生（SE））的影响，分子生物学技术的进步有助于揭示其作用背后的机制。乙烯对再生的影响不容忽视。这种化合物对再生的影响因物种、基因型和外植体而异。在某些物种中，乙烯似乎能使再生能力低的基因型恢复再生能力。然而，其作用并非累加性的，因为在再生能力高的基因型中，乙烯前体存在时这种能力会降低，这表明再生受乙烯调节。多条证据表明，乙烯在再生中的作用与生物和非生物胁迫以及激素相互作用显著相关，特别是与生长素和细胞分裂素家族的关键再生激素和生长调节剂。乙烯反应因子（ERF）家族的转录因子受乙烯调节，并与体细胞胚胎发生诱导密切相关。因此，乙烯、胁迫反应和再生能力之间的明显联系显著确立。在这篇综述中，讨论了乙烯的作用及其在器官发生和体细胞胚胎发生过程中与其他因素相互作用的方式。进一步研究乙烯在再生过程中诱导的ERF基因表达的调控，有助于深入了解乙烯在这些过程中的具体作用。由于一些乙烯信号成分与组蛋白乙酰化直接相关，应考虑其在表观遗传修饰中的可能作用。
