Istituto di Biologia Agroambientale e Forestale, CNR, 00016, Monterotondo Scalo, Roma, Italy.
Dipartimento di Scienze Agrarie, Alimentari e Agro-ambientali, Università di Pisa, 56124, Pisa, Italy.
Physiol Plant. 2017 Dec;161(4):486-501. doi: 10.1111/ppl.12611. Epub 2017 Sep 27.
β-1,3-glucans such as paramylon act as elicitors in plants, modifying the hormonal levels and the physiological responses. Plant hormones affect all phases of the plant life cycle and their responses to environmental stresses, both biotic and abiotic. The aim of this study was to investigate the effects of a root treatment with Euglena gracilis paramylon on xylem hormonal levels, photosynthetic performance and dehydration stress in tomato (Solanum lycopersicum). Paramylon granules were processed to obtain the linear fibrous structures capable to interact with tomato cell membrane. Modulation of hormone levels (abscisic acid, jasmonic acid and salicylic acid) and related physiological responses such as CO assimilation rate, stomatal and mesophyll conductance, intercellular CO concentration, transpiration rate, water-use efficiency, quantum yield of photosystem II and leaf water potential were investigated. The results indicate a clear dose-dependent effect of paramylon on the hormonal content of xylem sap, photosynthetic performance and dehydration tolerance. Paramylon has the capability to enhance plant defense capacity against abiotic stress, such as drought, by modulating the conductance to CO diffusion from air to the carboxylation sites and improving the water-use efficiency.
β-1,3-葡聚糖，如副淀粉，作为植物中的激发子，改变激素水平和生理反应。植物激素影响植物生命周期的所有阶段及其对生物和非生物环境胁迫的反应。本研究旨在研究用绿眼虫副淀粉对番茄（Solanum lycopersicum）木质部激素水平、光合作用和脱水胁迫的影响。副淀粉颗粒经过处理，获得能够与番茄细胞膜相互作用的线性纤维结构。研究了激素水平（脱落酸、茉莉酸和水杨酸）的调节以及相关的生理反应，如 CO 同化率、气孔和叶肉导度、胞间 CO 浓度、蒸腾速率、水分利用效率、光系统 II 的量子产率和叶片水势。结果表明，副淀粉对木质部汁液中激素含量、光合作用和耐旱性有明显的剂量依赖效应。副淀粉通过调节从空气到羧化部位的 CO 扩散的导度并提高水分利用效率，从而增强植物对干旱等非生物胁迫的防御能力。
