Functional Analysis of the Genotypic Differences in Response of Pea (Pisum sativum L.) to Calcareous-Induced Iron Deficiency

Abstract

Lime-induced iron chlorosis is a major nutritional disorder causing severe plant growth and yield reduction in the calcareous soils of Tunisia. The understanding the behavior of key metabolic functions of peas on calcareous soils, the identification of useful traits of tolerance, and the exploration of the genotypic differences in response to this constraint remain the most efficient approaches due to their coast, environmental benefits, and sustainability. For this purpose, a greenhouse experiment was conducted on three pea genotypes (Alexandra: Alex, Douce de provence: DP, and Merveille de Kelvedon: MK) cultivated on calcareous soil (Fe-deficient) and fertile soil (control). Plant growth, SPAD index, iron nutrition and distribution, photosynthesis, and antioxidant enzymes were deeply analyzed to discriminate genotypic differences. Calcareous-induced iron deficiency reduced SPAD index, plant growth, net photosynthesis, and tissue Fe content against a significant stimulation of the oxidative stress indicators, H2O2 and Malondialdehyde (MDA). Moreover, we reported a significant induction of SOD and CAT activity in shoots and roots of the Alexandra genotype. Fe use efficiency increased on calcareous soil and clearly discriminated the studied genotypes. Alexandra genotype was found to be the most tolerant to lime-induced iron chlorosis. This genotype protects its tissues against oxidative stress by stimulating enzyme activities (SOD and CAT) and develops significant efficiency of Fe uptake, translocation to shoots and use when cultivated on calcareous soil.