pH regulation during NO3 assimilation in shoots: 1 vacuole C RCOO-T RCOOH Suc C2小 NO3 amino-N etc shoot xylem phloem root Ignores root No reduction protein NO3 synthesis NOso
pH regulation during NO3 - assimilation in shoots: 1 NO3 - NO3 - C+ CO2 suc. shoot root xylem phloem pH Ignores root NO3 - reduction & protein synthesis light NO3 - C+ RCOO- RCOOH amino-N etc H+ vacuole
pH regulation during NO3 assimilation in shoots: 2 NO3 amino-N etc light SUC CO2 K+ is 're-cycled H+ RCOO to roots with K RCOO which is decarboxylated xylem phloem root CO2 Ignores root No H reduction protein RH- RCOO NO3 synthesis H个
pH regulation during NO3 - assimilation in shoots: 2 CO2 suc. root xylem phloem pH Ignores root NO3 - reduction & protein synthesis light K+ H+ + RCOO- K+ is ‘re-cycled’ to roots with RCOO-which is decarboxylated K+ NO3 NO - 3 - K+ NO3 - amino-N etc RCOO- H+ [RH] CO2
pH regulation during NO3 assimilation in shoots: 2 NO3 amino-N etc light SUC CO2 H+ RCOO K xylem phloem root CO2 Ignores root No H reduction protein RH- RCOO NO3 synthesis H个
pH regulation during NO3 - assimilation in shoots: 2 CO2 suc. root xylem phloem pH Ignores root NO3 - reduction & protein synthesis light K+ H+ + RCOOK+ NO3 NO - 3 - K+ NO3 - amino-N etc RCOO- H+ [RH] CO2 ‘Excess’ anion uptake
Nitrate cytoplasm outside High Affinity TS ve PD 高亲合力的运输系统 2) re-cycles' by co- CO transport O transport or H个 CO 2H+ Low Affinity TS Transport 低亲合力的运输系统 NO3i channel Energetics, kinetics, regulation, genes: Forde Clarkson(1999); Glass et al. (2002)
cytoplasm outside -ve PD H+ → 2H+ ) NO3 - ) 2H+ ) NO3 - ) NO3 - channel Energetics, kinetics, regulation, genes : Forde & Clarkson (1999); Glass et al. (2002) Nitrate cotransport cotransport or H+ ‘re-cycles’ by cotransport High Affinity TS 高亲合力的运输系统 Low Affinity TS 低亲合力的运输系统 pH
Plasma membrane transporters: summary Nitrate cytoplasm outside Balance sheet outside ve PD +1H+-[2H+1NO3] CO 2) -1[H+NO3] transport or or:+1OH-1N○3 excess anion influx CO 2H+ pH Transport Ignores Ct uptake: as When NO, is reduced in roots
cytoplasm outside -ve PD H+ → 2H+ ) NO3 - ) 2H+ ) NO3 - ) Ignores C+ uptake: as when NO3 - is reduced in roots Nitrate Plasma membrane transporters: summary cotransport cotransport Balance sheet outside: +1H+ -[2H+ + 1NO3 - ] = -1[H+ + NO3 - ] or: +1OH- -1NO3 - ( = ‘excess anion influx’) or pH