زيادة قدرة حشيش الرودس على تحمل ملوحة مياه الري في دولة الإمارات العربية المتحدة باستخدام الأكينوبكتيريا النافعة التي تعيش داخل جذور النباتات

الملخص EN

Nowadays, arable lands in the United Arab Emirates (UAE) have become uncultivable due to increased salinity in these lands or in groundwater used for irrigation.

To solve this problem, farmers use desalination plants for salty underground water, regardless of its cost and high maintenance.

High salt stress has negative effects on plant growth, development and productivity due to increased concentration of salt ions (i.e., NaCl) and the phytohormone ethylene (ET).

The purpose of this study is to find an innovative solution to increase tolerance of rhodes grass (Chloris gayana) to saline groundwater by using actinobacteria that secrete the enzyme, 1-aminocyclopropane-1- carboxylic acid (ACC) deaminase, which in turn reduces ET contents in planta.

To achieve this, three (out of 28) endophyticand four (out of 33) rhizospheric actinobacteria species simultaneously produced ACC deaminase and plant growth regulators (PGRs) such as auxin, gibberellins, cytokinins and amines.

In greenhouse experiments, treatments of actinobacteria living within the roots and in the soil significantly (P<0.05) increased the shoot and root growth of rhodes grass compared to control treatments under high salt irrigation water.

In addition, we showed a significant increase in the endogenous PGRs, but a significant decrease in ET in actinobacteria-treated plants.

This is the first report in the UAE or GCC to use a safe, environmentally-friendly and costeffective way to increase plant tolerance to salinity.

Improving growth parameters of rhodes grass using endophytic actinobacteria opens the doors to increase the production of animal feed as well as greening the desert under high salt conditions.