Pandey Veena, Tiwari Deep C, Dhyani Vibhash, Bhatt Indra D, Rawal Ranbeer S, Nandi Shyamal K
G. B. Pant National Institute of Himalayan Environment (GBPNIHE), Kosi-Katarmal, Almora, Uttarakhand 263 643 India.
Physiol Mol Biol Plants. 2021 Jul;27(7):1523-1538. doi: 10.1007/s12298-021-01027-w. Epub 2021 Jul 3.
Jones and Ham-ex-Smith are important medicinal herbs of the Himalayan region, which are highly demanded by pharmaceutical industries. Climatic variability especially increasing temperature and water deficit affects the growth and productivity of these species. In addition, increased temperature and water deficit may trigger the biosynthesis of medicinally important bioactive metabolites, which influence the quality of raw plant material and finished products. Therefore, and plants were undertaken and subjected to different levels of drought (no irrigation), heat (35 °C), and combined stresses for investigating their physiological and metabolic responses. Both the treatments (individually and in combination) reduced relative water content, photosynthesis, carboxylation efficiency, chlorophyll content, while increased intracellular CO, malondialdehyde and HO content in both the species. Transpiration and stomatal conductance increased under heat and reduced under drought stress as compared to control. Water use efficiency was found to be increased under drought, while reduced under heat stress. Protein, proline, carotenoid content and antioxidant enzymes activities (superoxide dismutase, peroxidise, catalase) initially increased and thereafter decreased during late stages of stress. Exposure of plants to combined stress was more detrimental than individual stress. In , exposure to drought stress significantly ( < 0.05) increased valerenic acid content in all plant parts (1.0-6.9 fold) with maximum increase after 20 days of exposure, while under heat stress, valerenic acid content increased (1.0-1.2 fold) in belowground part of and decreased (1.1-1.3 fold) in aerial part as compared to control. In exposure of individual heat stress for 25-30 days and combined stress for 5-15 days significantly ( < 0.05) increased linalool content to 6.2-6.5 fold and 8.3-19.6 fold, respectively, as compared to control. Higher accumulation of bioactive compounds after exposure to mild stress provides encouraging prospects for enhancing pharmaceutical properties of these Himalayan herbs.
The online version contains supplementary material available at 10.1007/s12298-021-01027-w.
琼斯草和哈梅克斯 - 史密斯草是喜马拉雅地区重要的药用植物，制药行业对其需求量很大。气候变异性，尤其是气温升高和水分亏缺，会影响这些物种的生长和生产力。此外，温度升高和水分亏缺可能会触发具有重要药用价值的生物活性代谢物的生物合成，这会影响生药材和成品的质量。因此，对这两种植物进行了不同程度的干旱（不灌溉）、高温（35℃）以及复合胁迫处理，以研究它们的生理和代谢反应。两种处理（单独和组合）均降低了相对含水量、光合作用、羧化效率、叶绿素含量，同时增加了两种植物细胞内的二氧化碳、丙二醛和过氧化氢含量。与对照相比，蒸腾作用和气孔导度在高温下增加，在干旱胁迫下降低。发现水分利用效率在干旱下增加，而在热胁迫下降低。蛋白质、脯氨酸、类胡萝卜素含量和抗氧化酶活性（超氧化物歧化酶、过氧化物酶、过氧化氢酶）在胁迫后期最初增加，随后降低。植物暴露于复合胁迫比单独胁迫更具危害性。在琼斯草中，暴露于干旱胁迫显著（P＜0.05）增加了所有植物部位的缬草酸含量（1.0 - 6.9倍），暴露20天后增加最多，而在热胁迫下，与对照相比，哈梅克斯 - 史密斯草地下部分的缬草酸含量增加（1.0 - 1.2倍），地上部分降低（1.1 - 1.3倍）。在哈梅克斯 - 史密斯草中，单独热胁迫处理25 - 30天和复合胁迫处理5 - 15天，与对照相比，芳樟醇含量分别显著（P＜0.05）增加至6.2 - 6.5倍和8.3 - 19.6倍。暴露于轻度胁迫后生物活性化合物的更高积累为增强这些喜马拉雅草药的药用特性提供了令人鼓舞的前景。
在线版本包含可在10.1007/s12298 - 021 - 01027 - w获取的补充材料。
