Plant Physiology Laboratory, Department of Botany, C.M.P. Degree College, A Constituent Post Graduate College of University of Allahabad, Prayagraj, 211002, India.
Crop Nanobiology and Molecular Stress Physiology Lab Amity, Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida, 201313, India.
Plant Reprod. 2024 Mar;37(1):33-36. doi: 10.1007/s00497-023-00479-2. Epub 2023 Aug 18.
Petal is one of the most esthetic and essential parts of a flower that fascinates the pollinators to enhance pollination. Petal senescence is a highly controlled and organized natural phenomenon assisted by phytohormones and gene regulation. It is an inelastically programmed event preceding to which petals give rise to color and scent that captivate pollinators, representing a flower's maturity for sexual reproduction. Till today, many genes involved in the petal senescence through genetic as well as epigenetic changes in response to hormones have been identified. In most of the species, petal senescence is controlled by ethylene, whereas others are independent of this hormone. It has also been proved that the increase in the carbohydrate contents like mannitol, inositol and trehalose delayed the senescence in tulips and Gladiolus. An increased sugar content prevents the biosynthesis of EIN3-like mRNA and further upregulates several senescence correlated genes. A wide range of different transcription factors as well as regulators are disparately expressed in ethylene insensitive and ethylene sensitive petal senescence. DcHB30, a downregulating factor, which upon linking physically to DcWRKY75 leads to the upregulation of ethylene promoting petal senescence. Here we describe the role of ethylene in petal senescence through epigenetic changes. Studies show that ethylene causes petal senescence through epigenetic changes. Feng et al. (Plant Physiol 192:546-564, 2023) observed that ARABIDOPSIS HOMOLOG OF TRITHORAX1 (DcATX1) promotes trimethylation of histone 3 (H3) at 4th lysine (H3K4me3) in Carnation. H3K4me3 further stimulates the expression of genes of ethylene biosynthesis and senescence, leading to senescence in Carnation.
花瓣是花朵最具美感和重要的部分之一，它吸引传粉者以增强授粉。花瓣衰老（Petal senescence）是一个高度受控和组织有序的自然现象，受植物激素和基因调控的辅助。这是一个不可逆转的程序化事件，在此之前，花瓣会产生颜色和气味，吸引传粉者，代表花朵成熟以进行有性繁殖。直到今天，许多涉及花瓣衰老的基因已经通过遗传和激素响应的表观遗传变化被识别出来。在大多数物种中，花瓣衰老受乙烯控制，而其他物种则不受这种激素控制。已经证明，碳水化合物含量的增加，如甘露醇、肌醇和海藻糖，会延迟郁金香和唐菖蒲的衰老。糖含量的增加可以防止 EIN3 样 mRNA 的生物合成，并进一步上调几个与衰老相关的基因。在乙烯不敏感和敏感的花瓣衰老中，广泛的不同转录因子和调节剂都有差异表达。DcHB30 是一种下调因子，它与 DcWRKY75 物理结合，导致促进乙烯的花瓣衰老基因上调。在这里，我们描述了通过表观遗传变化乙烯在花瓣衰老中的作用。研究表明，乙烯通过表观遗传变化导致花瓣衰老。Feng 等人（2023 年，《植物生理学》，第 192 卷：546-564）观察到拟南芥同源物 TRITHORAX1（DcATX1）促进康乃馨中组蛋白 3（H3）第 4 位赖氨酸（H3K4me3）的三甲基化。H3K4me3 进一步刺激乙烯生物合成和衰老相关基因的表达，导致康乃馨衰老。
