NUTRIENT SUPPLY AND GROWTH OF SEMINAL ROOT-SYSTEM IN BARLEY .3. COMPENSATORY INCREASES IN GROWTH OF LATERAL ROOTS, AND IN RATES OF PHOSPHATE UPTAKE, IN RESPONSE TO A LOCALIZED SUPPLY OF PHOSPHATE
NUTRIENT SUPPLY AND GROWTH OF SEMINAL ROOT-SYSTEM IN BARLEY .3. COMPENSATORY INCREASES IN GROWTH OF LATERAL ROOTS, AND IN RATES OF PHOSPHATE UPTAKE, IN RESPONSE TO A LOCALIZED SUPPLY OF PHOSPHATE
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DOI：
10.1093/jxb/29.2.435
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发表时间：
1978-01-01
影响因子：
6.9
通讯作者：
SAKER, LR
中科院分区：
文献类型：
--
作者：
DREW, MC;SAKER, LR
研究了连续流动溶液培养中生长的大麦 [Hordeum vulgare] 对局部磷酸盐供应的反应。根系统要么均匀地供应50μM磷酸盐（对照），要么将相同的溶液供应至仅4cm或2cm长度的种子根（局部供应），根系统的其余部分接受缺乏磷酸盐的营养液。在未从外部溶液中吸收磷酸盐的根系部分，侧枝发育很少，而在富含磷酸盐的 4 cm 区域，侧枝的数量和延伸有所增加。与对照的类似区域相比，21 天植物的侧枝总长度增加了 15 倍。此外，每单位根重的 32P-磷酸盐吸收率和向芽的转移率比对照高 2.5-5.0 倍。当最初供应磷酸盐的节段限制为仅 2 厘米时，侧根生长和磷酸盐吸收率进一步增加。这些对根系生长和磷酸盐吸收的局部改变很大程度上弥补了根系其余部分磷酸盐供应的不足。经过早期的生长迟缓和磷酸盐胁迫后，植物的相对生长速率和芽中磷酸盐的浓度恢复到与对照相似的水平。讨论了磷酸盐供应控制根系发育的方式，以及根系生长、磷酸盐吸收和芽生长之间协调的性质。
Responses to a localized supply of phosphate were studied in barley [Hordeum vulgare] grown in continuous flow solution culture. Root systems were either uniformly supplied with 50 .mu.M phosphate (controls) or the same solution was supplied to only a 4 cm or 2 cm length of a seminal root (localized supply), the remainder of the root system receiving a nutrient solution lacking phosphate. Little development of laterals occurred on those parts of the root system receiving no phosphate from the external solution, while an increase in the number and extension of laterals took place in the 4 cm zone enriched with phosphate. Compared with similar zones on controls, the total length of laterals was increased 15-fold in 21 day plants. In addition, rates of 32P-phosphate uptake and translocation to shoots per unit root weight were higher than in controls by a factor of 2.5-5.0. Further increases in the growth of lateral roots, and rates of phosphate uptake, were induced when the segment initially supplied with phosphate was restricted to only 2 cm. These localized modifications to root growth and uptake of phosphate largely compensated for the deficient supply of phosphate to the remainder of the root system. After an early period of retarded growth and phosphate stress, the relative growth rate of plants and the concentration of phosphate in shoots were restored to levels similar to that of the controls. The manner in which the supply of phosphate may control root development, and the nature of the co-ordination between root growth, phosphate uptake and shoot growth, are discussed.