Photosynthetic responses to phosphorus nutrition in two-year-old maritime pine seedlings.
Photosynthetic responses to phosphorus nutrition in two-year-old maritime pine seedlings.
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DOI：
10.1093/treephys/19.11.707
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发表时间：
1999-09
期刊：
影响因子：
4
通讯作者：
D. Loustau;M. B. Brahim;J. Gaudillère;E. Dreyer
中科院分区：
文献类型：
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作者：
D. Loustau;M. B. Brahim;J. Gaudillère;E. Dreyer
我们分析了限制光合作用的过程中，两年的年龄，容器生长的Pinus pinaster Ait。幼苗受到磷（P）缺乏。停磷3个月后，在养分循环系统中，以0、0.005、0.01和0.02d（-1）4个相对添加量对幼苗进行供磷。在第12周和第22周，测定了光合作用对CO（2）和光照的响应，并推导出以下参数：Rubisco羧化的最大速度，V（m）;电子传递的表观量子效率，α最大电子传递速率，J（m）;气孔导度和光合作用的相对气孔限制。在第22周，将这些测量与叶绿素荧光的同时测量相结合，以确定PSII的量子产率，以及用于再生羧化和氧化RuBP的组分之间的总光驱动线性电子流的理论分配。治疗12周后，针P浓度范围为0.04至0.15 x 10（-2）g g（DW）（-1），然后保持恒定，直至第22周。J（m）、α和V（m）值随针叶磷浓度的增加而增加（在最低和最高针叶磷浓度下，分别从30到133 mol m（-2）s（-1）、0.02到0.25 mol mol mol（-1）和13到78 mol CO（2）m（-2）s（-1）。在环境条件下，缺磷幼苗的净同化速率在饱和光照下受V（m）的限制，在限制光照下受J（m）的限制，而不受丙糖-P再生的限制。在用于羧化和氧化的级分之间的总光驱动线性电子流的分配中没有可检测到的变化。低磷浓度下幼苗黎明前光化学效率显著降低。虽然气孔导度有下降的趋势，减少针P浓度，相对气孔限制没有显着影响。在第22周，磷营养对V（m）的影响减弱，α和J（m）增加，这可能与生长停止和自然辐照度的季节性下降有关。
We analyzed processes limiting photosynthesis in two-year-old, container-grown Pinus pinaster Ait. seedlings subjected to phosphorus (P) deficiency. After withholding P for 3 months, seedlings were supplied P at four relative addition rates (0, 0.005, 0.01 and 0.02 day(-1)) in a nutrient recycling system. At Weeks 12 and 22, responses of photosynthesis to CO(2) and irradiance were measured and the following parameters derived: maximal velocity of carboxylation by Rubisco, V(m); apparent quantum efficiency of electron transport, alpha maximal electron transport rate, J(m); stomatal conductance and relative stomatal limitation of photosynthesis. At Week 22, these measurements were combined with concurrent measurements of chlorophyll fluorescence to determine the quantum yield of PSII, and a theoretical partitioning of total light-driven linear electron flow between fractions used to regenerate carboxylated and oxygenated RuBP. After 12 weeks of treatment, needle P concentrations ranged from 0.04 to 0.15 x 10(-2) g g(DW) (-1), and then remained constant until Week 22. Values of J(m), alpha and V(m) increased with increasing needle P concentration (from 30 to 133 mol m(-2) s(-1), 0.02 to 0.25 mol mol(-1) and 13 to 78 mol CO(2) m(-2) s(-1) at the lowest and highest needle P concentrations, respectively). Under ambient conditions, net assimilation rates in P-deficient seedlings were limited by V(m) under saturating irradiance, and by J(m) under limiting irradiance, but not by triose-P regeneration. There was no detectable change in the partitioning of total light-driven linear electron flow between the fractions used for carboxylation and oxygenation. Predawn photochemical efficiency of PSII was significantly reduced in seedlings with low P concentrations. Although stomatal conductance tended to decrease with decreasing needle P concentration, relative stomatal limitation was not significantly affected. At Week 22, there was an attenuation of the effects of P nutrition on V(m) and an increase in alpha and J(m) that was probably related to cessation of growth and the seasonal decline in natural irradiance.