2001 Fiscal Year Final Research Report Summary
MORPHOLOGICAL ANALYSIS ON THE MECHANISM OF NITRATE-INHIBITION OF ROOT NODULE FORMATION IN SOME LEGUMES ASSOCIATED WITH DIFFERENT RHIZOBIA
| Project/Area Number |
12660017
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
作物学
|
|---|
| Research Institution | OSAKA PREFECTURE UNIVERSITY |
|---|
Principal Investigator |
DAIMON Hiroyuki OSAKA PREFECTURE UNIVERSITY, GRADUATE SCHOOL OF AGRICULTURE AND BIOLOGICAL SCIENCES, ASSOCIATE PROFESSOR, 農学生命科学研究科, 助教授 (50236783)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Keywords | Crotalaria / Growth pouch method / Gus-marked gene / Microscope slide method / Nitrate / Nitrogen fixation / Rhizobia / Sesbania |
|---|
| Research Abstract |
Inhibitory effects of nitrate on initial stages of root nodule formation in S. rostrata and Crotalaria sp. were investigated by using a microscope slide culture method and a growth pouch culture method. The results are summarized as follows ;
1. In S. rostrata, formation of root, nodules was affected by the nitrate concentration. Seven days after Inoculating, the number of nodules were the lowest in the presence of nitrate at 5 mM, and the highest at 0 mM. Nitrate applied at 5 mM markedly reduced the number of lateral roots. This treatment also inhibited rhizobial attachment to the root surface, on which the blue colored area was detected by X-Gluc staining. Formation of root nodule primodia in the lateral root tissue was observed in resin-embedded sections. Observations of the agar-embedded sections revealed that the nodule development was definitely delayed in the presence of nitrate at 5 mM.
2. Root nodule formation and nitrogenase activity in two species of Crotalaria grown in a growth pouch were inhibited by application of nitrate to culture solution. Dry weight, surface areas, and total length of the roots of C. spectabilis were also reduced by application of nitrate at 10 mMN, suggesting that nitrate inhibited root nodule formation through reduction of the root growth.
3. The culture techniques with a microscope slide or a growth pouch might be rather convenient to clarify the inhibitory relationship between the structure of root system and nodule formation in the tested legume species. Further investigation of the mechanisms on the rhizobia-infection process and inhibitory effect of nitrate is now in progress.
|
Research Products
(24 results)
