The effect of mechanical impedance on root growth in pea (Pisum sativum).: I.: Rates of cell flux, mitosis, and strain during recovery
The effect of mechanical impedance on root growth in pea (Pisum sativum).: I.: Rates of cell flux, mitosis, and strain during recovery
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DOI：
10.1034/j.1399-3054.1999.100304.x
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发表时间：
1999-11-01
影响因子：
6.4
通讯作者：
Pritchard, J
中科院分区：
文献类型：
--
作者：
Croser, C;Bengough, AG;Pritchard, J
我们研究了机械阻抗对豌豆根细胞通量和分生组织活性的影响。豌豆幼苗 (Pisum sativum L, cl. Helka) 在填充至干燥堆积密度的沙芯中生长； 1.4 Mg m(-3)，并在表面施加额外的2.4 kg单轴载荷，以增加机械生长阻力（穿透阻力1.5 MPa）；或1.0 Mg m(-3)（侵彻阻力0.05 MPa）。选择 0.06 g g(-1) 的含水量以实现最佳根系生长。 3天后，将幼苗转移到水培中，添加秋水仙碱，评估细胞倍增率、有丝分裂指数和细胞周期长度，计算立即从沙子中取出的根的第三皮层细胞通量：机械阻抗使根伸长减慢至无阻碍速率的约20%，最终细胞长度减少至无阻碍长度的50%。对于从机械阻抗中恢复的根来说，细胞倍增速度慢了 3.4 倍，主要是由于间期花费的时间较长。受阻根中的细胞通量约为无阻根的一半（5 个细胞·h(-1)），并导致细胞排列和伸长区域更短，根伸长速率更慢。
We studied the effect of mechanical impedance on cell flux and meristematic activity in pea roots. Pea seedlings (Pisum sativum L, cl. Helka) were grown in cores of sand packed to dry bulk densities of either; 1.4 Mg m(-3) with an additional 2.4 kg uniaxial load applied to the surface to increase the mechanical resistance to growth (penetration resistance of 1.5 MPa); or 1.0 Mg m(-3) (penetration resistance of 0.05 MPa). A water content of 0.06 g g(-1) was chosen for optimum root growth. After 3 days, the seedlings were transferred to hydroponics, colchicine was added and the rate of cell doubling, mitotic index and length of the cell cycle was assessed, Cell flux in the third cortical layer was calculated for roots immediately removed from sand:Mechanical impedance slowed root extension to about 20% of the unimpeded rate, and final cell length was reduced to 50% of the unimpeded length. The rate of cell doubling was 3.4 times slower for roots recovering from mechanical impedance mostly as a result of a longer period spent in interphase. Cell flux in impeded roots was approximately half that of unimpeded roots (5 cells h(-1)), and contributed to a shorter cell file and elongation zone, and a slower rate of root elongation.