TY - JOUR
T1 - Empowering rice seedling growth by endophytic Bradyrhizobium sp. SUTN9-2
AU - Greetatorn, T.
AU - Hashimoto, S.
AU - Sarapat, S.
AU - Tittabutr, P.
AU - Boonkerd, N.
AU - Uchiumi, T.
AU - Teaumroong, N.
N1 - Funding Information:
This work was supported by Suranaree University of Technology, Kagoshima University, the Office of the Higher Education Commission under NRU project of Thailand, the National Research Council of Thailand, the Japan Society for the Promotion of Science and the Royal Golden Jubilee Ph.D. program.
Publisher Copyright:
© 2019 The Society for Applied Microbiology
PY - 2019/3
Y1 - 2019/3
N2 - Bradyrhizobium sp. strain SUTN9-2 was confirmed as rice endophytic bacteria and also as rice growth promotion agent. SUTN9-2 showed the capability of plant growth promotion characteristics, such as indole-3-acetic acid (IAA) and 1-amino-cyclopropane-1-carboxylic acid (ACC) deaminase productions and nitrogen fixation. In this study, the ability of SUTN9-2 to stimulate rice growth was investigated at different stages with N-free and NH4NO3 under in vivo condition. The rice dry weight and chlorophyll content could be enhanced when SUTN9-2 was inoculated in N-free, especially at seedling stage (7 and 14 dai). The rice dry weight was also increased when SUTN9-2 was inoculated with NH4NO3 at 7 and14 dai. The results of quantitative analysis of IAA and ACC deaminase were inconsistent with the expression of genes involved in IAA (nit) and ACC deaminase (acdS) productions. This inconsistently could implied that IAA and ACC deaminase produced from SUTN9-2 do not directly affect rice growth, but other factors resulting from the production of IAA and ACC deaminase could be involved. Moreover, the expression of genes involved in nitrogen fixation (nifH and nifV) of SUTN9-2 was also induced in rice tissues. This finding suggested that rice growth promotion may be supported by NH4NO3 together with nitrogen fixation by SUTN9-2. Significance and Impact of the Study: Indole-3-acetic acid, 1-amino-cyclopropane-1-carboxylic acid deaminase productions and nitrogen fixation may play important roles in rice growth promotion by endophytic SUTN9-2, especially at early rice seedling growth stage, which has the potential to be used as rice seedling growth promoter in the system of rice intensification.
AB - Bradyrhizobium sp. strain SUTN9-2 was confirmed as rice endophytic bacteria and also as rice growth promotion agent. SUTN9-2 showed the capability of plant growth promotion characteristics, such as indole-3-acetic acid (IAA) and 1-amino-cyclopropane-1-carboxylic acid (ACC) deaminase productions and nitrogen fixation. In this study, the ability of SUTN9-2 to stimulate rice growth was investigated at different stages with N-free and NH4NO3 under in vivo condition. The rice dry weight and chlorophyll content could be enhanced when SUTN9-2 was inoculated in N-free, especially at seedling stage (7 and 14 dai). The rice dry weight was also increased when SUTN9-2 was inoculated with NH4NO3 at 7 and14 dai. The results of quantitative analysis of IAA and ACC deaminase were inconsistent with the expression of genes involved in IAA (nit) and ACC deaminase (acdS) productions. This inconsistently could implied that IAA and ACC deaminase produced from SUTN9-2 do not directly affect rice growth, but other factors resulting from the production of IAA and ACC deaminase could be involved. Moreover, the expression of genes involved in nitrogen fixation (nifH and nifV) of SUTN9-2 was also induced in rice tissues. This finding suggested that rice growth promotion may be supported by NH4NO3 together with nitrogen fixation by SUTN9-2. Significance and Impact of the Study: Indole-3-acetic acid, 1-amino-cyclopropane-1-carboxylic acid deaminase productions and nitrogen fixation may play important roles in rice growth promotion by endophytic SUTN9-2, especially at early rice seedling growth stage, which has the potential to be used as rice seedling growth promoter in the system of rice intensification.
KW - 1-amino-cyclopropane-1-carboxylic acid-deaminase
KW - bradyrhizobia
KW - early rice growth promotion
KW - indole-3-acetic acid
KW - nitrogen fixation
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U2 - 10.1111/lam.13114
DO - 10.1111/lam.13114
M3 - Article
C2 - 30637774
AN - SCOPUS:85061093607
SN - 0266-8254
VL - 68
SP - 258
EP - 266
JO - Letters in Applied Microbiology
JF - Letters in Applied Microbiology
IS - 3
ER -