交替氧化酶通過(guò)控制ROS的產(chǎn)生來(lái)影響植物對(duì)生物脅迫的反應(yīng)

1、Alternative oxidase impacts the plant response to biotic stress by influencing the mitochondrial generation of reactive oxygen speciesPLANT CELL&ENVIRONMENT4.666introduction inoculation of tobacco with Pseudomonas syringae incompatible pv. maculicola results in a rapid and persistent burst of su

2、peroxide (O2-) from mitochondria, no change in amount of mitochondrial alternative oxidase (AOX) and induction of the hypersensitive response (HR). However, inoculation with incompatible pv.phaseolicola resulted in increased AOX, no O2-burst and no HR. Plants were grown in controlled environment cha

3、mbers (Model PGR-15, Conviron, Winnipeg, MB, Canada) with a 16 h photoperiod, temperature of 28 C/22 C (light/dark), relative humidity of 60%, photosynthetic photon flux density of 130 mmol m-2s-1, Plants were irrigated with water daily and fertilized with 10 x diluted Hoaglands solution three times

4、 per week. Plants were used 56 weeks after initiating germination in vermiculite. density was adjusted to 1 *107cfu mL-1 for plant inoculations. Plants were inoculated at 5 h into the light period. Mock-inoculated plants were infiltrated with distilled water. P. syringae pv. maculicolameasure of HR

5、cell deathWTRI29RI9P. syringae pv. phaseolicola.Results2P. syringae pv. phaseolicola. P. syringae pv. maculicola. AOX level remains low after inoculation with pv. maculicola ，but increases rapidly in response to pv. phaseolicola5WTRI29RI9P. syringae pv. maculicolaP. syringae pv.phaseolicola. the abs

6、olute level of H2O2 was not statistically different between the WT and transgenic lines after inoculation, owing it seems to the differences in the initial level of this ROS species between WT and transgenic plants.Inoculation with pv.maculicola， the amount of ONOO-In response to pv. maculicola, NO

7、level89The amount of NOThe amount of ONOO-the results mirrored those seen with O2-11AA ， NO的變化的變化WTRI29B7AA ， ONOO-的變化的變化discussion the level of AOX is an important determinant of the mitochondrial O2- burst O2- burst is not, in itself, sufficient to generate the HR. This is not surprising and is co

8、nsistent with hypotheses that the HR is dependent upon multiple coordinating signals that are invoked in response to some incompatible interactions the mitochondrial O2-burst does promote the HRWTRI29RI9NO levelH2O2 level3WTRI29RI9P. syringae pv. maculicolamitochondrial O2- The O2-burst normally see

9、n towards pv. maculicola is delayed in plants lacking AOX. This delay is associated with a delayed HR, suggesting that the burst does promote the HR. the mitochondrion is a target of biotic stressAApv. maculicolaO2-NOONOO- A O2-burst can also be induced by the complex III inhibitor antimycin A (AA),

10、 but is again delayed in plants lacking AOX. The similar mitochondrial response induced by pv. maculicola and AA suggests that electron transport is a target during HR-inducing biotic interactions.conclusion However, we did not see changes in the dynamics of NO generation by these plants in response to bacteria. The transgenic plants did not show an NO burst in response to pv. phaseolicola and they did not show a delayed NO burst, like they did for O2-, in response to pv.maculicola. This suggests that, while AOX leve