Effect of Kaolin and Fulvic Acid Antitranspirants on Tomato Plants Grown under Different Water Regimes

Abstract

Plant aquaporin genes regulate water movement through cellular membranes and determine the plant water relationship and plant adaptation to different environmental stresses. The expression of three PIP genes and one TIP gene was studied in response to PEG-induced dehydration in four Egyptian commercial wheat varieties. Semiquantitative estimation of RNA level via cDNA synthesis and PCR was used. Results showed that variations among the four studied genes in wheat varieties under normal condition and in the presence of PEG. Under normal conditions, Misr1 exhibited the highest level of PIP1 expression, Sids1 exhibited the highest level of PIP2 and PIP3 expression, and Gemmiza7 exhibited the highest expression of TIP1. Under dehydration induced by PEG, all three PIP genes (PIP1, PIP2, PIP3) showed various levels of transcription downregulation. PIP1 gave the highest level of downregulation in all varieties. Sids1 showed the highest response to PEG-induced dehydration because under normal conditions it exhibited high PIP expression and low TIP expression, whereas under dehydration condition it showed high downregulation of PIP genes and high upregulation of the TIP gene. This would be related to its high adaptation to dehydration. Results of this study will enhance our understanding of plant aquaporin expression profile and utilizing this in improvement of plant tolerance to dehydration.