Document Type : Original Article
Authors
1
Ph.D, graduate, Department of Biology-Plant Physiology, Faculty of Science, Golestan University, Gorgan, Iran
2
Professor, Department of Biology-Plant Physiology, Faculty of Science, Golestan University, Gorgan, Iran
3
Professor, Department of Plant Biology, Faculty of Biological Scuience, Tarbiat Modares University, Tehran, Iran
4
Assistant Professor, Department of Soil and Water Research, Golestan Agricultural and Natural Resources Research Center, Gorgan, Iran
10.22034/plant.2025.143111.1145
Abstract
Azospirillum is one of the most important Plant Growth Promoting Rhizobacteria (PGPR) which has capacity to fix atmospheric nitrogen. This study was conducted to investigate the effect of two Azospirillum species inoculation with auxin (IAA) and gibberellin (GA3) treatment on the antioxidant enzymes activity and some biochemical factors during their entry into the rice (Oryza sativa var. shiroodi) roots seedlings. Rice seedlings were grown in Yoshida medium for 21 days and then were inoculated with A. brasilense and A. irakens in the presence of 0, 100, and 200 ppm of IAA or GA3 alone or a combination of both. After 4 weeks treatment, roots of seedlings was harvested and used to study the activity of antioxidants and biochemical factors. The experiment was performed in complete randomized design with 3 replications. The obtained results showed that the activity of superoxide dismutase, ascorbate peroxidase and guaiacol-peroxidase enzymes were significantly increased in seedlings which inoculated with A. brasilense in combinations with IAA plus GA3 treatment. On the other hand, the activity of catalase, poly phenol oxidase and wall peroxidase was significantly decreased after inoculating with bacteria and IAA and GA3 treatment. Meanwhile, the amount of total and soluble protein and sugar was significantly increased after inoculation with bacteria and hormones treatment, compared to control samples. It seems enzymatic antioxidant system provide necessary conditions for bacteria entry into rice root organ.
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