Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4
The objective of this study was to assess the effect of selected pesticides [herbicides (metribuzin and glyphosate), insecticides (imidacloprid and thiamethoxam) and fungicides (hexaconazole, metalaxyl and kitazin)] at recommended and higher dose rates on plant growth promoting activities of the Mes...
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doaj-7e14dd3950894b779e6ec323aa2608022020-11-24T22:40:26ZengElsevierJournal of the Saudi Society of Agricultural Sciences1658-077X2012-01-01111637110.1016/j.jssas.2011.10.001Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4Munees AhemadMohammad Saghir KhanThe objective of this study was to assess the effect of selected pesticides [herbicides (metribuzin and glyphosate), insecticides (imidacloprid and thiamethoxam) and fungicides (hexaconazole, metalaxyl and kitazin)] at recommended and higher dose rates on plant growth promoting activities of the Mesorhizobium sp. isolated from chickpea-nodules. A total of 50 rhizobial strains recovered from the nodules of chickpea root systems were identified following morphological, biochemical and host-specificity tests and tested for pesticide-tolerance. Among these strains, the Mesorhizobium sp. strain MRC4 was specifically selected due to the highest tolerance levels for all selected pesticides and the maximum production of plant growth promoting substances. Strain MRC4 produced indole acetic acid (44 μg ml−1), siderophores [salicylic acid (35 μg ml−1) and 2,3-dihydroxy benzoic acid (19 μg ml−1)], exo-polysaccharides (21 μg ml−1), HCN and ammonia. Under pesticide-stress, pesticide-concentration dependent progressive-decline in all plant growth promoting traits of the Mesorhizobium sp. strain MRC4 exposed was observed except for exo-polysaccharides which consistently increased with exceeding the concentration of each pesticide from recommended dose. For instance, hexaconazole at three times the recommended dose elicited the maximum stress on siderophore-biosynthesis by the Mesorhizobium sp. strain MRC4 and decreased salicylic acid and DHBA by 40% and 47%, respectively and the greatest stimulatory effect on exo-polysaccharides secretion was shown by imidacloprid which stimulated the Mesorhizobium sp. strain MRC4 to secrete EPS by 38%, compared to control. Generally, the maximum toxicity to plant growth promoting traits of Mesorhizobium was shown by glyphosate, thiamethoxam and hexaconazole, at three times the recommended rate among herbicides, insecticides and fungicides, respectively. This study revealed an additional aspect of the toxicological mechanisms of the pesticides through which they suppress the plant growth.http://www.sciencedirect.com/science/article/pii/S1658077X1100052XChickpeaMesorhizobiumPesticidePlant growth promoting rhizobacteriaToleranceToxicity |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Munees Ahemad Mohammad Saghir Khan |
spellingShingle |
Munees Ahemad Mohammad Saghir Khan Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4 Journal of the Saudi Society of Agricultural Sciences Chickpea Mesorhizobium Pesticide Plant growth promoting rhizobacteria Tolerance Toxicity |
author_facet |
Munees Ahemad Mohammad Saghir Khan |
author_sort |
Munees Ahemad |
title |
Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4 |
title_short |
Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4 |
title_full |
Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4 |
title_fullStr |
Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4 |
title_full_unstemmed |
Effects of pesticides on plant growth promoting traits of Mesorhizobium strain MRC4 |
title_sort |
effects of pesticides on plant growth promoting traits of mesorhizobium strain mrc4 |
publisher |
Elsevier |
series |
Journal of the Saudi Society of Agricultural Sciences |
issn |
1658-077X |
publishDate |
2012-01-01 |
description |
The objective of this study was to assess the effect of selected pesticides [herbicides (metribuzin and glyphosate), insecticides (imidacloprid and thiamethoxam) and fungicides (hexaconazole, metalaxyl and kitazin)] at recommended and higher dose rates on plant growth promoting activities of the Mesorhizobium sp. isolated from chickpea-nodules. A total of 50 rhizobial strains recovered from the nodules of chickpea root systems were identified following morphological, biochemical and host-specificity tests and tested for pesticide-tolerance. Among these strains, the Mesorhizobium sp. strain MRC4 was specifically selected due to the highest tolerance levels for all selected pesticides and the maximum production of plant growth promoting substances. Strain MRC4 produced indole acetic acid (44 μg ml−1), siderophores [salicylic acid (35 μg ml−1) and 2,3-dihydroxy benzoic acid (19 μg ml−1)], exo-polysaccharides (21 μg ml−1), HCN and ammonia. Under pesticide-stress, pesticide-concentration dependent progressive-decline in all plant growth promoting traits of the Mesorhizobium sp. strain MRC4 exposed was observed except for exo-polysaccharides which consistently increased with exceeding the concentration of each pesticide from recommended dose. For instance, hexaconazole at three times the recommended dose elicited the maximum stress on siderophore-biosynthesis by the Mesorhizobium sp. strain MRC4 and decreased salicylic acid and DHBA by 40% and 47%, respectively and the greatest stimulatory effect on exo-polysaccharides secretion was shown by imidacloprid which stimulated the Mesorhizobium sp. strain MRC4 to secrete EPS by 38%, compared to control. Generally, the maximum toxicity to plant growth promoting traits of Mesorhizobium was shown by glyphosate, thiamethoxam and hexaconazole, at three times the recommended rate among herbicides, insecticides and fungicides, respectively. This study revealed an additional aspect of the toxicological mechanisms of the pesticides through which they suppress the plant growth. |
topic |
Chickpea Mesorhizobium Pesticide Plant growth promoting rhizobacteria Tolerance Toxicity |
url |
http://www.sciencedirect.com/science/article/pii/S1658077X1100052X |
work_keys_str_mv |
AT muneesahemad effectsofpesticidesonplantgrowthpromotingtraitsofmesorhizobiumstrainmrc4 AT mohammadsaghirkhan effectsofpesticidesonplantgrowthpromotingtraitsofmesorhizobiumstrainmrc4 |
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