| Autor: |
Majumdar, Arkajo, Kar, Rup Kumar |
| Předmět: |
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| Zdroj: |
Journal of Plant Growth Regulation; Aug2023, Vol. 42 Issue 8, p5280-5293, 14p |
| Abstrakt: |
Plasma membrane located NADPH oxidase (NOX) and H+-ATPase function cooperatively during early root growth to maintain the membrane electrical balance while mediating cell growth through wall relaxation. A potent transcriptional co-regulation of the two enzymes has also been identified which further highlights the essentiality of NOX-PM H+-ATPase feed-forward loop, mediated by H2O2 and Ca+ 2, during root growth. The pathway from superoxide (O2˙ˉ) generation to cell elongation involves intermediary conversion of O2˙ˉ to H2O2 by superoxide dismutase (SOD) and subsequently by class III peroxidase (Prx) to produce ˙OH radical, necessary for wall polysaccharide cleavage. Present work demonstrates further the involvement of polyamine metabolism in the ROS-mediated process of root growth regulation. Thus, in addition to retardation of root growth, inhibition of PAO (polyamine oxidase) results in significant diminution of NOX and PM H+-ATPase activities. On the other hand, exogenous application of PAs (viz. putrescine, spermidine and spermine) stimulates the NOX-PM H+-ATPase cascade resulting in augmented production of O2˙ˉ and H2O2. Interestingly, blocking of NOX and PM H+-ATPase activities (through specific inhibitors) as well as quenching of their products (through dedicated antagonistic agents) drastically reduced PAO activity as observed in both spectrophotometric and native PAGE assays. Inhibition of PAO has also been recorded when treated with Ca+ 2-chelator and Ca+ 2-channel blocker. Correlating the present observations with earlier findings it has been hypothesized that H2O2 and Ca+ 2 are serving as mediators of interplay between NOX-PM H+-ATPase cascade and PA metabolism during early root growth in Vigna radiata (L.) Wilczek seedlings. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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