The effect of L-TRP on growth and
yield of rice could be attributed to either auxin
metabolites produced by the rhizosphere microflora
which were subsequently taken up by plant roots or
direct uptake of L-TRP by the plant roots with
subsequent catabolism into auxins within the plant
tissue and/or alteration in the balance of the
rhizosphere microbial community in response to LTRP
addition which may affect growth and yield of
rice.