Conserved transport mechanisms but distinct auxin responses govern shoot patterning in Selaginella kraussiana.
Conserved transport mechanisms but distinct auxin responses govern shoot patterning in Selaginella kraussiana.
复制标题
克劳斯卷柏的运输机制保守，但生长素反应不同，控制着芽的形成。
作者：
H. Sanders;J. Langdale
为了提供一个比较的框架来理解维管植物中生长素调节的进化，我们在卷柏中检测了生长素动态平衡的影响。生长素的极性运输是通过示踪离体枝条中的氚-生长素来测量的。芽在生长素外流抑制剂和外源生长素存在的情况下培养，并记录了发育异常。卷柏枝条中的生长素运输完全是基瓣的，与被子植物中的生长素一样。生长素运输受扰会导致分生组织维持功能丧失和枝条构型异常。卷柏的二分根分枝似乎受到生长素和细胞分裂素之间的拮抗关系的调节。这些结果表明，在番茄和真叶植物的共同祖先中存在着基瓣生长素的极地运输。虽然生长素的运输机制似乎在所有维管植物中都是保守的，但在番茄和真叶植物中，不同的生长素反应控制着枝条的生长和发育。
To provide a comparative framework to understand the evolution of auxin regulation in vascular plants, the effect of perturbed auxin homeostasis was examined in the lycophyte Selaginella kraussiana. Polar auxin transport was measured by tracing tritiated IAA in excised shoots. Shoots were cultured in the presence of auxin efflux inhibitors and exogenous auxin, and developmental abnormalities were documented. Auxin transport in Selaginella shoots is exclusively basipetal, as in angiosperms. Perturbed auxin transport results in the loss of meristem maintenance and abnormal shoot architecture. Dichotomous root branching in Selaginella appears to be regulated by an antagonistic relationship between auxin and cytokinin. The results suggest that basipetal polar auxin transport occurred in the common ancestor of lycophytes and euphyllophytes. Although the mechanisms of auxin transport appear to be conserved across all vascular plants, distinct auxin responses govern shoot growth and development in lycophytes and euphyllophytes.