Wall yield threshold and effective turgor in growing bean leaves
Wall yield threshold and effective turgor in growing bean leaves
复制标题
豆叶生长过程中壁产量阈值和有效膨压
作者：
E. Volkenburgh;R. Cleland
细胞膨大率取决于细胞壁延展性(M)和超过壁产量阈值的膨压(P)。差异(P-Y)是生长有效膨胀率(Pe)。测定了菜豆(Phaseolus Common garisL.)用等压干湿计，用应力松弛法导出Y。当叶片在光照条件下开始快速生长时，P、Y和PEALL降低。此后，当成熟叶片的生长速度下降时，Y继续减小，而Pe实际上增加。这些数据证实了早期的结果，即光刺激叶片生长速率的变化主要由INM的变化控制，而不是由INPE的变化控制。在100%相对湿度下培养的幼苗，磷含量增加，但不能提高生长速度。在某些情况下，Y的变化与P平行，因此保持不变。这些数据表明，在将细胞膨胀率与生长速度联系起来时，确定Pe而不仅仅是P是很重要的。
The rate of cell enlargement depends on cell-wall extensibility (m) and on the amount of turgor pressure (P) which exceeds the wall yield threshold (Y). The difference (P-Y) is the growth-effective turgor (Pe). Values ofP, YandPehave been measured in growing bean (Phaseolus vulgarisL.) leaves with an isopiestic psychrometer, using the stress-relaxation method to deriveY. When rapid leaf growth is initiated by light,P, YandPeall decrease. Thereafter, while the growth rate declines in maturing leaves,Ycontinues to decrease andPeactually increases. These data confirm earlier results indicating that the changes in light-stimulated leaf growth rate are primarily controlled by changes inm, and not by changes inPe. Seedlings incubated at 100% relative humidity have increasedP, but this treatment does not increase growth rate. In some casesYchanges in parallel withP, so thatPeremains unchanged. These data point out the importance of determiningPe, rather than justP, when relating cell turgor to the growth rate.