Relative contributions of polyamines and arbuscular mycorrhiza in modulating nickel induced physiological and biochemical responses in cajanus cajan l Millsp

Abstract

Roles of polyamines (PAs-Spm, Spd and Put) and Rhizoglomus intraradices (AM)in mitigating nickel (Ni)-induced toxic responses in pigeonpea genotypes were investigated. Presence of Ni reduced nutrient uptake, which degraded photosynthetic pigments and ultimate yield. PAs and AM could reduce Ni uptake, with AM most efficient, followed by Put, Spd and Spm respectively. AM complemented rhizobial symbiosis and improved N2-fixing potential by providing nutrients (P and N) to the symbiosomes. Both amendments increased PAs biosynthesis, which balanced the redox status of plants. Furthermore, all treatments strengthened enzymatic and non-enzymatic antioxidant defense mechanisms, where AM was more promising than PAs. Interestingly, Put primed AM inoculated plants were most efficient in ameliorating Ni stress in pigeonpea plants newline