ABSTRACT
The heavy metals encounter the roots of the plant and thus this soil accumulated with metal adversely affects root growth resulting in hampering the overall growth performance of the plants. Plant stresses like oxidative, metals toxicity, drought and salinity, and extreme temperatures along with the attack of insects, pests, and plant pathogens result in limited crop productivity by adversely affecting various physiological and molecular activities of plants which is a serious threat to agriculture. Proline is a nitrogen containing five-carbon-amino acid that acts as an osmoprotectant, free radical scavenger, antioxidant, and protein stabilizer and metal chelator. Soluble sugars such as glucose, sucrose, trehalose, and related oligosaccharides have an active role in growth regulation, photosynthesis, carbon partitioning, osmotic homeostasis, membrane stabilization, and gene expression under various abiotic stresses. This chapter focuses on several phytohormones involved in the regulation of heavy metal tolerance.
