抄録
Bacteria colonize the exterior and interior habitat of leaves, or phyllosphere, nourished by sugars and other products of plant metabolism. To establish a population on a leaf, a bacterium must be able to overcome several abiotic and biotic stresses including plant-derived potentially toxic hydrogen peroxide (H2O2). Here we report that H2O2 tolerance of Rhodococcus sp. strain APG1, in relation to nitric oxide (NO) production by cells cultured on a variety of C sources. Relative to cells grown on other sources of C, sucrose-grown cells were found to reach lower growth yields and show higher tolerance to H2O2 that correlated with increased formation of NO. The results suggest that sucrose may enhance H2O2 tolerance of Rhodococcus APG1 by increasing cellular NO producing capacity. We propose a regulatory role for NOS in promoting tolerance of Rhodococcus APG1 to oxidative stress in the phyllosphere.
