Some bacteria produce substances that stimulate
the growth of plants in the absence of
pathogens. The best understood example is
the hormone auxin. In addition, other hormones
as well as certain volatiles and the cofactor
pyrrolquinoline quinone (PQQ) stimulate
plant growth.
The root-growth-promoting hormone
auxin, as present in root exudate, is usually
synthesized from the exudate amino acid
tryptophan. The tryptophan concentration in
exudate differs strongly among plants (41, 48).
Inoculation of seeds with the auxin-generating
P. fluorescens WCS365 did not result in an increase
in the root or shoot weight of cucumber,
sweet pepper, or tomato, but led to a significant
increase in the root weight of radish. Radish
produces at least nine times more tryptophan
in its exudate per seedling than cucumber,
sweet pepper, or tomato (41). An example of
bacterial stimulation of radish growth is shown
Some bacteria produce substances that stimulatethe growth of plants in the absence ofpathogens. The best understood example isthe hormone auxin. In addition, other hormonesas well as certain volatiles and the cofactorpyrrolquinoline quinone (PQQ) stimulateplant growth.The root-growth-promoting hormoneauxin, as present in root exudate, is usuallysynthesized from the exudate amino acidtryptophan. The tryptophan concentration inexudate differs strongly among plants (41, 48).Inoculation of seeds with the auxin-generatingP. fluorescens WCS365 did not result in an increasein the root or shoot weight of cucumber,sweet pepper, or tomato, but led to a significantincrease in the root weight of radish. Radishproduces at least nine times more tryptophanin its exudate per seedling than cucumber,sweet pepper, or tomato (41). An example ofbacterial stimulation of radish growth is shown
การแปล กรุณารอสักครู่..
