Phytohormones Responses of Ricinus communis to Saline Soils and Regulation of Biosynthetic Hormone Pathways

Abstract

This study has been conducted to assess and analyze the nature of saline soil characteristics and their effect on Phytohormones responses of Ricinus communis has been studied for four-season in four different sites. Samples were collected seasonally for the period February 2018 to January 2019, taken from four selected sites in (Najaf), Iraq. four levels of saline soils were cultivated with the halophyte species (Ricinus communis). The soils had the following salinity levels:
1) Nonsaline soil (S1, 0.9 dS. m–1) 2) Slightly saline soil (S2, 4.2 dS. m–1) 3) Moderately saline soil (S3, 7.2 dS m–1) 4) Highly saline soil (S4, 14.1 dS m–1)
The environmental factors of Soil were additionally evaluated for electrical conductivity, pH, and soil ion concentrations prior to planting. Hormones play crucial roles in the plant’s response to saline stress. In Winter (GA) and (Za) free contents enhanced to first response then (IAA) bound contents at Spring then (IAA) free contents in Summer at last (ABA) bound contents in Autumn as a gradual response to increasing saline stress. In general, it can be used Phytohormones’ contents as an indicator of saline stresses. It is also possible for species adapted to these environments to be used as salt-tolerant gene materials to enhance conventional crops during selection, breeding and improving environments. The water may change gene expression, which is reflected in a change in the nuclear gene cloning, which raising (ABA) level.