Effect of Pseudomonas fluorescent on proline and phytohormonal status of maize (Zea mays L.) under water deficit stress.

Phytohormones play critical roles in regulating plant growth and its response to stress. This experiment was conducted to study the relationship between water deficiency and Pseudomonas fluorescent on proline amino acid and some phytohormones in maize (704 Hybrid). Experimental design was split plot in the form of randomized complete block design (RCBD) with three replications. Treatments included four Pseudomonas strains and a non-inoculated control treatment as sub plots in three levels of water deficit according to 40% (control), 60% and 75% of available soil moisture depletion. Results showed that drought stress triggered a change in plant phytohormonal balance, including an increase in leaf proline and abscisic acid (ABA) content, and a decline in auxin, gibberelline and cytokinin. However, inoculated plants had increased proline, abscisic acid, auxin, gibberelline and cytokinin content. Plants inoculated with P. fluorescens strain 153 showed the highest mean of proline, abscisic acid, auxin, gibberelline and cytokinin content in the leaves. This study indicates that application of PGPR can enhance phytohormones content of maize under water deficit stress condition.