Hybrid weakness controlled by the dosage-dependent lethal (DL) gene system in common bean (Phaseolus vulgaris) is caused by a shoot-derived inhibitory signal leading to salicylic acid-associated root death
Hybrid weakness controlled by the dosage-dependent lethal (DL) gene system in common bean (Phaseolus vulgaris) is caused by a shoot-derived inhibitory signal leading to salicylic acid-associated root death
复制标题
DOI：
10.1111/j.1469-8137.2007.02215.x
复制
发表时间：
2007-01-01
期刊：
影响因子：
9.4
通讯作者：
Pilbeam, David J.
中科院分区：
文献类型：
--
作者：
Hannah, Matthew A.;Kraemer, K. Melanie;Pilbeam, David J.
普通豆（Phaseolus vulgaris）的某些杂交导致与严重根系表型相关的温度依赖性杂交弱。这是由根和茎表达的半显性等位基因剂量依赖性致死1 （DL1）和DL2的相互作用控制的，这两个等位基因通过远距离信号进行交流。以前，外源蔗糖对根系生长和恢复正常根系生长的明显互惠效应导致了剂量依赖性致死（DL）系统可能控制根冠碳分配的假设。本研究利用重组自交系对DL位点进行了定位，并利用生理生化分析（包括代谢物分析）对信号相互作用和根系表型有了新的认识。结果表明，DL系统不控制根冠碳分配，根系不太可能因碳饥饿而死亡。相反，正如水杨酸积累所表明的那样，根系死亡可能是由防御相关的程序性细胞死亡引起的。表达dl2的子叶提供了一个强有力的抑制信号，足以导致表达dl1的根死亡。这些数据暗示DL系统参与防御相关的信号传导，并为最近的假设提供了支持，即防御相关的自身免疫在植物物种形成中是一种潜在的隔离机制，特别是为远距离信号传导和温度依赖的潜在作用奠定了基础。
Certain crosses of common bean (Phaseolus vulgaris) result in temperature-dependent hybrid weakness associated with a severe root phenotype. This is controlled by the interaction of the root- and shoot-expressed semidominant alleles dosage-dependent lethal 1 (DL1) and DL2, which communicate via long-distance signaling. Previously, apparent reciprocal effects on root growth and the restoration of normal root growth by exogenous sucrose led to the hypothesis that the dosage-dependent lethal (DL) system may control root-shoot carbon partitioning.Here, recombinant inbred lines were used to map the DL loci and physiological and biochemical analysis, including metabolite profiling, was used to gain new insights into the signaling interaction and the root phenotype.It is shown that the DL system does not control root-shoot carbon partitioning and that roots are unlikely to die from carbon starvation. Instead, root death likely occurs by defense-related programmed cell death, as indicated by salicylic acid accumulation. DL2-expressing cotyledons supply a potent inhibitory signal that is sufficient to cause such death in DL1-expressing roots.These data implicate the DL system in defense-related signaling and provide support for the recent hypothesis of defense-related autoimmunity as a potential isolating mechanism in plant speciation, in particular, setting a precedence for the potential roles of long-distance signaling and temperature dependence.