The class IId bacteriocin thuricin-17 increases plant growth.
The mechanisms by which many plant growth promoting rhizobacteria (PGPR) affect plants are unknown. We recently isolated a rhizosphere bacterium (Bacillus thuringiensis NEB17), that promotes soybean growth and screened the liquid growth medium in which it grew for plant growth stimulating materials. We have also shown that it produces a bacteriocin (named by us as thuricin-17 and a member of the recently described class IId bacteriocins). Here we show that application of this bacteriocin to leaves (spray) or roots (drench) directly stimulates the growth of both a C(3) dicot (soybean) and a C(4) monocot (corn). This growth stimulation is similar in nature to that previously seen when plants are treated with Nod factors. Strain NEB17 contains three copies of the gene for thuricin 17 that code for identical amino acid sequences. These two lines of evidence suggest that the dual functions of these proteins may have constrained their evolution. This is the first report of direct plant growth enhancement by a bacteriocin.
Lee
Kyung Dong
KD
Department of Oriental Medicine Materials, Dongshin University, 252 Daeho-dong, Naju, Jeonnam, 520-714, South Korea.
Gray
Elizabeth J
EJ
Mabood
Fazli
F
Jung
Woo-Jin
WJ
Charles
Trevor
T
Clark
Scott R D
SR
Ly
Anh
A
Souleimanov
Alfred
A
Zhou
Xiaomin
X
Smith
Donald Lawrence
DL
D000595:Amino Acid Sequence; D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism; D001430:Bacteriocins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010788:Photosynthesis / Q000187:drug effects; D063245:Plant Development; D018515:Plant Leaves / Q000187:drug effects* / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development; D010944:Plants / Q000187:drug effects*; D053204:Root Nodules, Plant / Q000187:drug effects / Q000254:growth & development; D013025:Glycine max / Q000187:drug effects / Q000254:growth & development; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development
D001430:Bacteriocins; C059740:thuricin