硅/钾联合调控下燕麦应对盐碱胁迫的生理响应机制

Saline-alkali stress reduces plant uptake of K + and increases Na + uptake, resulting in salt toxicity and inhibition of plant growth. The Exogenous silicon or potassium (Si / K) could promote plant uptake of K + and alleviate the inhibition of salt stress on plant growth. However, the regulating effect and synergistic mechanism of Si / K on the physiological adaptability of oat plants, are not clear and still deserve further study. In this proposal, the project aims to study the physiological response mechanism of oats to salt and alkali stress under Si / K joint regulation, understanding the effects of Si / K and the interaction, distribution and interaction, and clarifying the mechanism of the interaction between mineral ions absorption as well as growth and physiological characteristics of different parts of oats controlled by Si / K . To the end, the mechanism of Si / K combined regulation of oat ion absorption and salinity tolerance under salt and alkali stress will be proposed. It is of great scientific significance and application value to the saline-alkali physiological regulation mechanism and the application of saline-alkali soil in saline-alkaline soil.

盐碱胁迫会降低植物对K+的吸收并增加对Na+的吸收，从而产生盐分毒害和抑制植物生长。施加外源硅或钾（Si/K）均能促进植物对K+的吸收，并缓解盐分胁迫对植物生长造成的抑制效应。然而针对盐碱胁迫下外源Si/K对燕麦生理适应性的分别调控效应和协同作用机制等问题还未有深入探究。为此，本项目拟就Si/K联合调控下燕麦应对盐碱胁迫的生理响应机制展开研究。通过研究Si/K对盐碱胁迫下燕麦生长和生理特性的影响规律，阐明盐碱胁迫下Si/K的分别作用，作用阈值和互作效应；探明Si/K对燕麦不同部位的离子迁移、累积和微区分布的影响规律，阐明Si/K调控燕麦不同部位的矿质离子吸收与其生长和生理特性之间的互馈效应，从而揭示盐碱胁迫下Si/K对燕麦离子吸收及其生理适应性的联合调控机制。该项目预期对燕麦的耐盐碱生理调控机制和盐碱地改良利用均具有重要的科学意义和实际应用价值。

盐碱胁迫会降低植物对K+的吸收并增加对Na+的吸收，从而产生盐分毒害和抑制植物生长。施加外源硅或钾（Si/K）能够促进植物对K+的选择性吸收，并缓解盐分胁迫对植物生长造成的抑制效应。本项目就Si/K联合调控下植物应对盐碱胁迫的生理响应机制展开研究。采用水培实验探究不同盐碱胁迫下，单独施加Si、K 或Si/K联合施用对黑麦草生长和生理特性的影响，低盐浓度（50mmol/L）下Si与Si+K处理对植物生长具有相同的促进效应，而高盐浓度（200mmol/L）只有Si和K 同时施用才能缓解盐分胁迫对植物生长的抑制效应。硅/钾混合施加，显著提高了黑麦草根、茎和叶内 K+/Na+，且显著降低了叶部 Na+，导致更多的 Na+存在于根部可溶性组分和细胞壁内，降低 Na+的毒害作用，较单独施加硅或钾具有显著优势。利用煤矸石和草木灰制备硅钾肥，由于煤矸石和草木灰在高温煅烧条件下生成了钾霞石、类沸石等易溶于弱酸的物质，从而促进了Si、K元素的溶出。将硅钾肥和醋糟拌施制备硅钾肥基改良剂，探究单一的硅肥、钾肥和硅钾肥及硅钾肥基改良剂对盐碱土的改良效应及盐碱生境中植物生长的调控，硅钾肥基改良剂的施入可以有效降低土壤pH，增加土壤团聚结构，同时能够有效促进盐碱胁迫下燕麦的生长和K离子的选择性吸收，降低盐碱胁迫对叶片的质膜损伤率，因此硅钾肥基改良剂相较单一的硅肥或钾肥对盐碱土壤具有明显的改良效应。该项目对植物的耐盐碱生理调控机制和盐碱地改良利用均具有重要的理论指导意义和科学价值。