TY - JOUR
T1 - Functional characterization of a soybean growth stimulator Bradyrhizobium sp. strain SR-6 showing acylhomoserine lactone production
AU - Ali, Amanat
AU - Ayesha,
AU - Hameed, Sohail
AU - Imran, Asma
AU - Iqbal, Mazhar
AU - Iqbal, Javed
AU - Oresnik, Ivan J.
N1 - Publisher Copyright:
© FEMS 2016.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - A soybean nodule endophytic bacterium Bradyrhizobium sp. strain SR-6 was characterized for production of acyl homoserine lactones (AHLs) as quorum sensing molecules. Mass spectrometry analysis of AHLs revealed the presence of C6-HSL, 3OH-C6-HSL, C8-HSL, C10-HSL, 3oxoC10-HSL, 3oxo-C12-HSL and 3OH-C12-HSL which are significantly different from those reported earlier in soybean symbionts. Purified AHL extracts significantly improved wheat and soybean seedling growth and root hair development along with increased soybean nodulation under axenic conditions. A positive correlation was observed among in vivo nitrogenase and catalase enzyme activities of the strain SR-6. Transmission electron microscopic analysis showed the cytochemical localization of catalase activity within the bacteroids, specifically attached to the peribacteroidal membrane. Root and nodule colonization proved rhizosphere competence of SR-6. The inoculation of SR-6 resulted in increased shoot length (13%), plant dry matter (50%), grain weight (16%), seed yield (20%) and N-uptake (14%) as compared to non-inoculated soybean plants. The symbiotic bacterium SR-6 has potential to improve soybean growth and yield in sub-humid climate of Azad Jammu and Kashmir region of Pakistan. The production and mass spectrometric profiling of AHLs as well as in vivo cytochemical localization of catalase enzyme activity in soybean Bradyrhizobium sp. have never been reported earlier elsewhere before our these investigations.
AB - A soybean nodule endophytic bacterium Bradyrhizobium sp. strain SR-6 was characterized for production of acyl homoserine lactones (AHLs) as quorum sensing molecules. Mass spectrometry analysis of AHLs revealed the presence of C6-HSL, 3OH-C6-HSL, C8-HSL, C10-HSL, 3oxoC10-HSL, 3oxo-C12-HSL and 3OH-C12-HSL which are significantly different from those reported earlier in soybean symbionts. Purified AHL extracts significantly improved wheat and soybean seedling growth and root hair development along with increased soybean nodulation under axenic conditions. A positive correlation was observed among in vivo nitrogenase and catalase enzyme activities of the strain SR-6. Transmission electron microscopic analysis showed the cytochemical localization of catalase activity within the bacteroids, specifically attached to the peribacteroidal membrane. Root and nodule colonization proved rhizosphere competence of SR-6. The inoculation of SR-6 resulted in increased shoot length (13%), plant dry matter (50%), grain weight (16%), seed yield (20%) and N-uptake (14%) as compared to non-inoculated soybean plants. The symbiotic bacterium SR-6 has potential to improve soybean growth and yield in sub-humid climate of Azad Jammu and Kashmir region of Pakistan. The production and mass spectrometric profiling of AHLs as well as in vivo cytochemical localization of catalase enzyme activity in soybean Bradyrhizobium sp. have never been reported earlier elsewhere before our these investigations.
KW - Acyl homoserine lactones
KW - Bradyrhizobium
KW - Catalase enzyme
KW - Nitrogenase activity
KW - Soybean
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U2 - 10.1093/femsec/fiw115
DO - 10.1093/femsec/fiw115
M3 - Article
C2 - 27242370
AN - SCOPUS:84985031434
SN - 0168-6496
VL - 92
JO - FEMS Microbiology Ecology
JF - FEMS Microbiology Ecology
IS - 9
M1 - fiw115
ER -
