Secondary metabolism responses in two Pisum sativum L. cultivars cultivated under Fe deficiency conditions

Abstract

The present study was carried out to investigate the Fe deficiency effect on the secondary metabolism  responses in two Pisum sativum cultivars characterized by different tolerance to Fe deficiency. Previous study  investigating the physiological responses to Fe deficiency in these two pea cultivars showed that Kelvedon was  more tolerant than Lincoln. Both cultivars were grown in the absence or presence of Fe with the addition of bicarbonate for twelve days. Higher concentrations of phenols and flavonoids were observed in Fe-deficient  tissues of both cultivars; however, the increase was greater in the tolerant cultivar than in the susceptible  one. The activity of shikimate pathway enzymes tested was more enhanced in the tolerant cultivar. In  addition, lipid peroxidation and H₂O₂ concentrations were more increased in the susceptible cultivar when  compared with the tolerant one. Peroxidase activity was increased in the tolerant cultivar grown under  bicarbonate supply, while a considerable diminution was observed in the susceptible one, suggesting the  involvement of this antioxidant enzyme in the tolerance of pea to Fe deficiency. The lignifying peroxidases  activity was more decreased in Lincoln than in Kelvedon, especially in the presence of bicarbonate. Our data  suggest that the tolerance of Kelvedon was related to its ability to modulate the phenolic metabolism pathway and to enhance the antioxidant potentials.

Key words: Iron deficiency, bicarbonate, phenolic metabolism, antioxidative enzymes, Pisum sativum.