[Characterization of root nodule and rhizobium of a Leguminosae ephemeral plant--Trigonella arcuata C. A. Mey in Xinjiang].
OBJECTIVE
We studied root nodule proliferation, nodule microstructure, genetic cluster and stress resistance of the rhizobium of Trigonella arcuata.


METHODS
We characterized root nodule and rhizobium with various soil matrixes cultivation, paraffin section, resin semi-ultrathin section techniques, and 16S rRNA gene cluster analysis.


RESULTS
(1) Plants grew in mixed soil (nutritious garden soil: poplar zone soil: desert sands = l:1:1), had the most nodule proliferation and bore the most pods. The shapes of nodule were palm- or ginger-like; (2) Microstructure of the nodule revealed five different parts differentiated within the nodule: epidermis (E), cortex (C), vascular bundle (VB), infected cells (IC) and uninfected cells (UIC); (3) Genetic cluster analysis of the full length 16S rRNA gene sequence (1377 bp) indicated that the rhizobium isolated shared the highest identities with Sinorhizobium meliloti; (4) The rhizobium could grow between 4 and 60 degrees C (20 min), pH 6.0-12.0 and 0-2% NaCl. For the antibiotic sensitivity, the rhizobium could not grow normally in medium with 25 microg/mL Kanamycin, Streptomycin or Cephalothin, except for 100 microg/mL Ampicillin.


CONCLUSIONS
Good conditions of soil matrixes were important for nodulation of T. arcuata; A large quantity of cells in fascicular nodules were infected by rhizobia; 16S rRNA gene sequence of T. arcuata shared the highest identities with that of Sinorhizobium meliloti, and this strain was able to tolerate relatively higher temperature and alkalin.
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830046, China. yty2002@163.com
Tianyu
T
You
Zhi
Z
Tan
Lili
L
Gu
Xiuming
X
Li
Shixiang
S
Yao
Haiyan
H
Lan
Fuchun
F
Zhang
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*; D053204:Root Nodules, Plant / Q000254:growth & development* / Q000648:ultrastructure*; D013312:Stress, Physiological; D013696:Temperature; D029910:Trigonella / Q000254:growth & development* / Q000648:ultrastructure*
D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S