Williams Michael L, Cobb A H
Department of Life Sciences, Trent Polytechnic, School of Science, Nottingham NG11 8NS, U.K.
New Phytol. 1988 Mar;108(3):285-290. doi: 10.1111/j.1469-8137.1988.tb04164.x.
A marked seasonal response was observed in the starch content of chloroplasts of Codium fragile sampled between November 1983 and November 1984. Chloroplast starch uniformly increased throughout the life-cycle of this alga, reaching a maximum in the summer months of approx. 5 mg glucose equivalents/10 plastids when C. fragile was in the reproductive phase. Chloroplast starch content was found to be inversely proportional to the concentration of stromal phosphate, decreasing linearly from 5 to 2 mg glucose equivalents/10 plastids over a range of stromal phosphate values of 0·75-1·5 μmol PO /10 plastids. Similarly, the net amount of starch synthesized over 3 h by isolated chloroplasts increased linearly with respect to initial chloroplast starch content. These observations are discussed in relation to the regulation of starch synthesis by variations in the stromal P : PGA ratio.
在1983年11月至1984年11月期间采集的脆弱仙菜叶绿体淀粉含量中观察到明显的季节性响应。在这种藻类的整个生命周期中，叶绿体淀粉均匀增加，在夏季达到最大值，当脆弱仙菜处于生殖阶段时，约为5毫克葡萄糖当量/10个质体。发现叶绿体淀粉含量与基质磷酸盐浓度成反比，在基质磷酸盐值为0·75 - 1·5 μmol PO₄³⁻/10个质体的范围内，从5毫克葡萄糖当量/10个质体线性下降至2毫克葡萄糖当量/10个质体。同样，分离的叶绿体在3小时内合成的淀粉净量相对于初始叶绿体淀粉含量呈线性增加。结合基质中P:PGA比例的变化对淀粉合成的调节来讨论这些观察结果。
