Changes in Ecophysiology, Osmolytes, and Secondary Metabolites of the Medicinal Plants of Mentha piperita and Catharanthus roseus Subjected to Drought and Heat Stress
Changes in Ecophysiology, Osmolytes, and Secondary Metabolites of the Medicinal Plants of Mentha piperita and Catharanthus roseus Subjected to Drought and Heat Stress
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DOI：
10.3390/biom10010043
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发表时间：
2020-01-01
期刊：
影响因子：
5.5
通讯作者：
Elkelish, Amr
中科院分区：
文献类型：
--
作者：
Alhaithloul, Haifa A.;Soliman, Mona H.;Elkelish, Amr
全球变暖导致全球大部分地区气温升高，降雨量减少。极端温度和缺水同时发生，导致植物遭受温度胁迫伤害。为了模拟更自然的田间环境，并弄清特定胁迫对它们组合的响应，我们以薄荷和长春花为材料，研究了干旱和高温胁迫(单独和联合)施加和恢复后的生理、生化和代谢变化。植物暴露在干旱和/或高温(35摄氏度)下7天和14天。胁迫显著降低了株高和株重(鲜重和干重)，高温和干旱联合处理的影响更为明显。干旱和/或热胁迫引起渗透调节物质(脯氨酸、糖、甘氨酸甜菜碱和包括肌醇和甘露醇在内的糖醇)的积累，其中最大的积累响应于复合胁迫。干旱胁迫后7天和14天，两种植物的总酚、黄酮类和皂苷含量均下降，但单宁、萜类和生物碱等次生代谢物含量在胁迫下均增加，在高温/干旱联合胁迫下积累量最大。这两种植物的叶提取物对致病真菌和细菌以及两种人类癌细胞株的生长都有显著的抑制作用。干旱和高温胁迫显著降低了植物的抑菌和抗癌活性。在干旱和/或热胁迫下观察到次生代谢物积累的增加，表明施加非生物胁迫可能是增加与这些植物相关的治疗性次生代谢物含量的一种策略。
Global warming contributes to higher temperatures and reduces rainfall for most areas worldwide. The concurrent incidence of extreme temperature and water shortage lead to temperature stress damage in plants. Seeking to imitate a more natural field situation and to figure out responses of specific stresses with regard to their combination, we investigated physiological, biochemical, and metabolomic variations following drought and heat stress imposition (alone and combined) and recovery, using Mentha piperita and Catharanthus roseus plants. Plants were exposed to drought and/or heat stress (35 degrees C) for seven and fourteen days. Plant height and weight (both fresh and dry weight) were significantly decreased by stress, and the effects more pronounced with a combined heat and drought treatment. Drought and/or heat stress triggered the accumulation of osmolytes (proline, sugars, glycine betaine, and sugar alcohols including inositol and mannitol), with maximum accumulation in response to the combined stress. Total phenol, flavonoid, and saponin contents decreased in response to drought and/or heat stress at seven and fourteen days; however, levels of other secondary metabolites, including tannins, terpenoids, and alkaloids, increased under stress in both plants, with maximal accumulation under the combined heat/drought stress. Extracts from leaves of both species significantly inhibited the growth of pathogenic fungi and bacteria, as well as two human cancer cell lines. Drought and heat stress significantly reduced the antimicrobial and anticancer activities of plants. The increased accumulation of secondary metabolites observed in response to drought and/or heat stress suggests that imposition of abiotic stress may be a strategy for increasing the content of the therapeutic secondary metabolites associated with these plants.