Photosynthetic gas exchange, plant water relations and osmotic adjustment of three tropical perennials during drought stress and re-watering

作者：Jie He, Klaudia Ng, Lin Qin, Yuanjie Shen, Harianto Rahardjo, Chien Looi Wang, Huiling Kew, Yong Chuan Chua, Choon Hock Poh, Subhadip Ghosh · 发表于：PLoS ONE · 年份：2024 · DOI：10.1371/journal.pone.0298908 · 被引用次数：10 · 研究领域：Plant Water Relations and Carbon Dynamics、Plant responses to water stress、Growth and nutrition in plants

Planting vegetation on slopes is an effective way of improving slope stability while enhancing the aesthetic appearance of the landscape. However, plants growing on slopes are susceptible to natural drought stress (DS) conditions which commonly lead to water deficit in plant tissues that affect plant health and growth. This study investigated the photosynthetic gas exchange, plant water status and proline accumulation of three tropical perennials namely Clerodendrum paniculatum, Ipomoea pes-caprae and Melastoma malabathricum after being subjected to DS and re-watering (RW). During DS, there was a significant decrease in light-saturated photosynthetic CO2 assimilation rate (Asat), stomatal conductance (gs sat), and transpiration rate (Tr) for all three plant species. Leaf relative water content, shoot water potential, and leaf, stem and root water content also declined during DS. Proline concentration increased for all three species during DS, reaching especially high levels for C. paniculatum, suggesting that it heavily relies on the accumulation of proline to cope with DS. Most of the parameters recovered almost completely to levels similar to well-watered plants after RW, apart from M. malabathricum. Strong linear correlations were found between Asat and gs sat and between gs sat and Tr. Ultimately, C. paniculatum and I. pes-caprae had better drought tolerance than M. malabathricum.