تأثیر ریزوباکترهای مولدACC دآمیناز جداسازی‌شده از مزارع گندم شهرستان پارس‌آباد مغان در پاسخ گندم به تنش خشکی و Bipolaris sorokiniana در شرایط گلخانه

Crops are exposed to various biotic and abiotic stresses. In nature, these stresses often affect the plant at the same time and in interaction with each other. The use of plant growth promoting bacteria (PGPB) is an alternative strategy to improve plant tolerance under stressful conditions. 1-Aminocyclopropane-1-carboxylate (ACC) deaminase-producing rhizobacteria cause stress tolerance by regulating plant ethylene levels. The aim of the present study was to investigate the effect of ACC-deaminase-producing rhizobacteria isolated from wheat fields of Parsabad-Moghan County in modulating the effects of drought stress and common root and crown rot disease caused by Bipolaris sorokiniana in wheat. The severity of this disease increases under drought stress conditions. These isolates were evaluated in terms of drought tolerance, ACC deaminase production, antagonistic activity against B. sorokiniana, inhibition of disease and development of plant growth characteristics at drought stress levels of 100%, 50% and 30% of field capacity in the greenhouse. Drought stress and disease decreased the height and wet weight of shoots, roots and the whole plant, relative water content, chlorophyll content and antioxidant enzyme activity, and increased hydrogen peroxide and cell osmolytes. Rhizobacteria moderated the morphological, physiological and biochemical responses of wheat to drought stress and disease, and in more severe stress (30% FC) condition they were able to have positive effects on wheat responses to deal with the simultaneous effects of stresses. Finally, 16S rRNA gene sequencing placed all isolates in Pseudomonas genus.
Keywords: Stress, Rhizobacteria, Wheat, ACC deaminase, 16S rRNA