Cluster-root formation and carboxylate release in three Lupinus species as dependent on phosphorus supply, internal phosphorus concentration and relative growth rate.
Cluster-root formation and carboxylate release in three Lupinus species as dependent on phosphorus supply, internal phosphorus concentration and relative growth rate.
复制标题
三种羽扇豆物种的簇根形成和羧酸盐释放取决于磷供应、内部磷浓度和相对生长速率。
DOI：
10.1093/aob/mct210
复制
发表时间：
2013
期刊：
影响因子：
4.2
通讯作者：
H. Lambers
中科院分区：
文献类型：
--
作者：
Xing Wang;Stuart J. Pearse;H. Lambers
背景和目标
一些羽扇豆属植物会产生丛生根，以响应植物低磷状态。丛根形成的羽扇豆种间丛根形成差异的原因尚不清楚。本研究的目的是研究当羽扇豆属植物表现出相似的地上部磷状况时，丛根的形成是否在一定程度上取决于它们之间不同的相对生长率(RGRs)。
方法
在0、7·5、15和40 mg P kg(-1)干沙条件下，在冲刷河沙中培育了3种丛根羽扇豆属植物：白羽扇豆、毛羽羽扇豆属和大西洋羽扇豆属。分别于播种后34、42、62d采收植株，测定不同树龄的叶、茎、丛根和非簇根的鲜重和干重。测定了丛根百分率、组织磷浓度、根系分泌物和植株相对生长率。
关键结果
磷处理对丛根分配有较大影响，当供磷量超过15mgP kg(-1)沙地时，黄花菜和黄花菜对丛根分配的抑制作用显著但不完全。在最高磷供应的情况下，大西洋龙须草被完全抑制；该物种从未在丛生根中投入超过其根重的20%。对于马尾松和大西洋马尾松，无论RGR如何，在较高的内部磷浓度下，丛根形成减少。对于白头翁，也有相同的趋势，但这并不显著。
结论
无论RGR如何，在较高的叶片磷浓度下，三种羽扇豆丛生根的形成都受到抑制。这三种植物丛根形成的差异不能用RGR或叶P浓度的物种差异来解释。
BACKGROUND AND AIMS
Some Lupinus species produce cluster roots in response to low plant phosphorus (P) status. The cause of variation in cluster-root formation among cluster-root-forming Lupinus species is unknown. The aim of this study was to investigate if cluster-root formation is, in part, dependent on different relative growth rates (RGRs) among Lupinus species when they show similar shoot P status.
METHODS
Three cluster-root-forming Lupinus species, L. albus, L. pilosus and L. atlanticus, were grown in washed river sand at 0, 7·5, 15 or 40 mg P kg(-1) dry sand. Plants were harvested at 34, 42 or 62 d after sowing, and fresh and dry weight of leaves, stems, cluster roots and non-cluster roots of different ages were measured. The percentage of cluster roots, tissue P concentrations, root exudates and plant RGR were determined.
KEY RESULTS
Phosphorus treatments had major effects on cluster-root allocation, with a significant but incomplete suppression in L. albus and L. pilosus when P supply exceeded 15 mg P kg(-1) sand. Complete suppression was found in L. atlanticus at the highest P supply; this species never invested more than 20 % of its root weight in cluster roots. For L. pilosus and L. atlanticus, cluster-root formation was decreased at high internal P concentration, irrespective of RGR. For L. albus, there was a trend in the same direction, but this was not significant.
CONCLUSIONS
Cluster-root formation in all three Lupinus species was suppressed at high leaf P concentration, irrespective of RGR. Variation in cluster-root formation among the three species cannot be explained by species-specific variation in RGR or leaf P concentration.
影响因子：
4.3
作者：
K. Yoneyama;K. Yoneyama;Y. Takeuchi;H. Sekimoto
通讯作者：
K. Yoneyama;K. Yoneyama;Y. Takeuchi;H. Sekimoto