In the crust of earth, silicon (Si) is one of the two major elements. For plant growth and development, importance of Si remains controversial due to the widely differences in ability of plants to take up this element. In this paper, pot experiments were done to study Si roles in improving salt, drought or cadmium (Cd) stress tolerance in wheat. Up to full emergence, all pots were watered at 100% field capacity (FC) every other day with nutrient solution without any treatments. Fifteen days after sowing, pots were divided into four plots, each with 40 pots for no stress (control) and three stress treatments; drought (50% FC), salinity (200 mM NaCl) and cadmium (2 mM Cd). For all plots, Si was applied at four levels (0, 2, 4 and 6 mM). Under no stress condition, Si applications increased Si content and improved growth as a result of reduced electrolyte leakage (EL), malondialdehyde (MDA) and Na⁺ contents. Under stress conditions, Si supplementation conferred higher growth, gas exchange, tissue water and membranes stabilities, and K⁺ content, and had limited MDA and Na⁺ contents and EL compared to those obtained without Si. Compared to those without Si, enzyme (e.g., superoxide dismutase, catalase and peroxidase) activity was improved by Si applications, which were linked with elevated antioxidants and osmoprotectants (e.g., free proline, soluble sugars, ascorbic acid and glutathione) contents, might providing antioxidant defense against abiotic stress in wheat. The level of 4 mM Si was most effective for mitigating the salt and drought stress conditions, while 6 mM Si level was most influentially for alleviating the Cd stress condition. These results suggest that Si is beneficial in remarkably affecting physiological phenomena and improving wheat growth under abiotic stress.

在地壳中，硅（Si）是两个主要元素之一。对于植物的生长和发育，由于植物吸收该元素的能力差异很大，因此硅的重要性仍存在争议。本文通过盆栽试验研究了硅在提高小麦盐，干旱或镉（Cd）胁迫耐受性中的作用。直到完全出苗，所有盆均隔天以100％田间灌溉量（FC）浇灌营养液，无需任何处理。播种十五天后，将盆分成四个样地，每个地上有40个无压力（对照）的盆和三种压力处理；干旱（50％FC），盐分（200 mM NaCl）和镉（2 mM Cd）。对于所有地块，均以四个级别（0、2、4和6 mM）施加Si。在没有压力的情况下，⁺内容。在胁迫条件下，Si的添加具有更高的生长，气体交换，组织水和膜的稳定性以及K ⁺含量，并且MDA和Na ⁺有限。含量和EL与没有Si获得的那些相比。与没有硅的那些相比，施用硅提高了酶（例如超氧化物歧化酶，过氧化氢酶和过氧化物酶）的活性，这与提高的抗氧化剂和渗透保护剂（例如游离脯氨酸，可溶性糖，抗坏血酸和谷胱甘肽）的含量有关。抗小麦非生物胁迫的抗氧化剂防御。4 mM Si的水平对于缓解盐分和干旱胁迫条件最为有效，而6 mM Si的水平对缓解Cd胁迫条件的影响最大。这些结果表明硅在显着影响生理现象和改善非生物胁迫下的小麦生长方面是有益的。