Soil & Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad 38000, Pakistan.
Soil & Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad 38000, Pakistan.
Ecotoxicol Environ Saf. 2015 Apr;114:126-33. doi: 10.1016/j.ecoenv.2015.01.017. Epub 2015 Jan 28.
Plants are the ultimate food source for humans, either directly or indirectly. Being sessile in nature, they are exposed to various biotic and abiotic stresses because of changing climate that adversely effects their growth and development. Contamination of heavy metals is one of the major abiotic stresses because of anthropogenic as well as natural factors which lead to increased toxicity and accumulation in plants. Arsenic is a naturally occurring metalloid toxin present in the earth crust. Due to its presence in terrestrial and aquatic environments, it effects the growth of plants. Plants can tolerate arsenic using several mechanisms like phytochelation, vacuole sequestration and activation of antioxidant defense systems. Several signaling mechanisms have evolved in plants that involve the use of proteins, calcium ions, hormones, reactive oxygen species and nitric oxide as signaling molecules to cope with arsenic toxicity. These mechanisms facilitate plants to survive under metal stress by activating their defense systems. The pathways by which these stress signals are perceived and responded is an unexplored area of research and there are lots of gaps still to be filled. A good understanding of these signaling pathways can help in raising the plants which can perform better in arsenic contaminated soil and water. In order to increase the survival of plants in contaminated areas there is a strong need to identify suitable gene targets that can be modified according to needs of the stakeholders using various biotechnological techniques. This review focuses on the signaling mechanisms of plants grown under arsenic stress and will give an insight of the different sensory systems in plants. Furthermore, it provides the knowledge about several pathways that can be exploited to develop plant cultivars which are resistant to arsenic stress or can reduce its uptake to minimize the risk of arsenic toxicity through food chain thus ensuring food security.
植物是人类的最终食物来源，无论是直接的还是间接的。由于自然的固着性，它们会受到各种生物和非生物胁迫的影响，因为气候变化会对它们的生长和发育产生不利影响。重金属污染是主要的非生物胁迫之一，这是由于人为和自然因素导致的毒性增加和积累在植物中的原因。砷是一种天然存在的类金属毒素，存在于地壳中。由于它存在于陆地和水生环境中，会影响植物的生长。植物可以通过几种机制来耐受砷，如植物螯合作用、液泡隔离和激活抗氧化防御系统。植物中已经进化出几种信号机制，涉及使用蛋白质、钙离子、激素、活性氧和一氧化氮作为信号分子来应对砷毒性。这些机制通过激活它们的防御系统，使植物能够在金属胁迫下生存。这些应激信号是如何被感知和响应的途径是一个尚未探索的研究领域，仍有许多空白需要填补。对这些信号通路的深入了解有助于培育出在砷污染土壤和水中表现更好的植物。为了提高植物在污染地区的存活率，强烈需要确定合适的基因靶点，这些基因靶点可以根据利益相关者的需求，使用各种生物技术进行修改。本综述重点介绍了在砷胁迫下生长的植物的信号机制，并深入了解了植物中的不同感觉系统。此外，它还提供了关于几种途径的知识，这些途径可以被开发利用来培育对砷胁迫具有抗性的植物品种，或者减少其吸收，以最大限度地降低通过食物链产生的砷毒性风险，从而确保食品安全。
