Developmental phase transitions in plants

在植物的一生中，经历着主要的发育相变，这取决于环境和内在因素。在植物形态上观察到的令人难以置信的变化通常来自于某些发育程序表达时间的变化。大多数关于植物发育阶段变化的研究都集中在单个事件上，即开花诱导。相比之下，调控早期发育阶段转变的分子机制仍然不清楚。我之前的研究强调了脱落酸和赤霉酸等脂溢性激素在植物发育过程的时间控制中发挥的异时调节下游作用的重要性。通过改变细胞分裂速率，这些激素也能够影响叶片的特性和对非生物胁迫的抵抗力。还有几个悬而未决的问题。例如，调节这些过程的分子机制是什么？这些途径在动物和植物之间以及在不同植物物种之间是保守的吗？我实验室的研究项目将集中在了解调控植物发育相变和叶片特性的分子机制，特别是激素在这些过程中所起的作用。我未来的研究旨在使用正向和反向遗传学方法以及基因组学工具来分离在拟南芥早期发育阶段变化中受到影响的突变体。化学遗传学还将被用来识别在相变过程中模仿、增强或抑制已知激素反应的新分子。通过这些类型的筛选鉴定的突变体稍后将使用现代荧光成像技术在分子、发育和细胞水平上进行表征。这项工作的目的是利用模式植物拟南芥来寻找新的发育阶段变化的主要调控因子，并进一步将这一研究扩展到不同的植物物种，以研究它们的功能在进化过程中是否保守。

During their lifetime, plants undergo major developmental phase transitions that are dependent on both environmental and intrinsic factors. The incredible variation observed in plant morphology often derives from changes in the timing of expression of certain developmental programs. Most of the research on developmental phase change in plants has focused on a single event, floral induction. In contrast, the molecular mechanisms that regulate early developmental phase transitions, are still poorly defined. My previous research has highlighted the importance of the role lipophillic hormones like abscisic acid and gibberellic acid play downstream of heterochronic regulators in the temporal control of developmental programs in plants. By changing the rate of cell division, these hormones are also able to affect leaf identity and resistance to abiotic stresses. Several open questions remain. For example, what are the molecular mechanisms that regulate these processes? Are these pathways conserved between animals and plants and among different plant species? Research projects in my lab will focus on understanding the molecular mechanisms that regulate developmental phase transitions and leaf identity in plants, and in particular, the role that hormones play in these processes. My future research aims to isolate mutants affected in early developmental phase changes in Arabidopsis using forward and reverse genetics approaches, as well as genomics tools. Chemical genetics will also be used to identify new molecules that mimic, enhance or suppress known hormone responses during phase transitions. Mutants identified through these types of screens will be later characterized at the molecular, developmental and cellular level using modern fluorescent imaging techniques. The aim of this work is to identify new master regulators of developmental phase changes using the model plant Arabidopsis and then further extend this study to different plant species in order to investigate whether their function is conserved during evolution.