Increasing plant growth and productivity by manipulating vascular development

气候模型和最近天气模式的变化强烈表明，我们正在进入一个时期，在这个时期，全球大部分地区更频繁地暴露在极端和多变的天气中。虽然这些变化对植物生长模式的影响尚不清楚，但提高生产率和克服气候变化不利影响的技术可能会越来越受到追捧。因此，有必要了解植物生长是如何调节的，以及即使面对波动或不利的环境条件，也可以在多大程度上操纵植物生长来提高生产力。在一年生植物拟南芥中，我们已经确定PXY控制形成层细胞分裂的多肽配体CLE41和受体激酶之间的信号传递，并已经证明操纵这一途径导致植物生长和种子产量的增加(Etchells和Turner，2010；Etchells等人，2012；Etchells等人，2013)。最近，我们已经证明，改变CLE41和PXY的杨树同源物的表达可以增加形成层细胞分裂，这表明这一途径在树木径向生长的进化中发挥了中心作用。这些基因的精确组织特异性表达导致生长增加了两倍。改变PXY-CLE不仅增加了维管细胞的分裂，而且还显示出非常大的植株高度和叶片大小的增加，这表明这一途径在调节植物生长方面具有更广泛的作用(Etchells等人，2014年)。这些结果表明，工程PXY/CLE41信号提供了一种提高植物生产力的方法，从一年生杂草拟南芥到杨树。项目目标：1。了解PXY-CLE如何调节植物生长。确定操纵PXY-CLE信号在多大程度上能够超越调节植物生长的环境刺激。更好地理解维管发育和植物生长之间的关系这将通过；1。寻找新的CLE信号分子进一步能够促进植物生长。研究光合作用能力改变的烟草植株，以了解光合作用、生长和维管发育之间的关系。3.研究促进维管束发育的其他途径也如何影响植物的生长。确定血管组织中的信号能够在多大程度上超越环境生长信号。Etchells，J.P.，Mishra，L.，Kumar，M.，Campbell，L.和Turner，S.R.(2014)。“通过操纵PXY调节的细胞分裂，增加了树木中木材的形成。”已提交。Etchells，J.P.，Provost，C.M.，Mishra，L.和Turner，S.R.(2013)。“Wox4和Wox14作用于PXY受体激酶下游，独立于血管组织中的任何角色调节植物的血管增殖”。开发区140,2224-2234。Etchells，J.P.，Provost，C.M.和Turner，S.R.(2012)。植物维管细胞分裂是通过PXY和乙烯信号之间的相互作用来维持的。PLOS Genet.8，e1002997 Etchells，J.P.和Turner，S.R.(2010)。PXY-Cle41受体配体对定义了一条控制血管细胞分裂速度和方向的多功能途径。发展137,767-774。

Climate models and recent changes in weather pattern strongly suggest that we are entering a period in which large parts of the globe experience more frequent exposure to extreme and changeable weather. While the effect of these changes on patterns of plant growth is unclear, technologies that increase productivity and overcome adverse effects of climate change are likely to be increasingly sought after. Consequently, there is a need to understand how plant growth is regulated and to what extent it can be manipulated to increase productivity even in the face of fluctuating or adverse environmental conditions. In the annual plant Arabidopsis, we have identified that signaling between a peptide ligand, CLE41 and a receptor kinase, PXY controls cambial cell divisions and have demonstrated that manipulating this pathway leads to an increase in both plant growth and seed production (Etchells and Turner, 2010; Etchells et al., 2012; Etchells et al., 2013). More recently we have been able demonstrate that altering the expression of the poplar homologues of CLE41 and PXY increases cambial cell division indicating a central role for this pathway in the evolution of radial growth in trees. Precise tissue-specific expression of these genes resulted in a two-fold increase in growth. No only did altering PXY-CLE increase vascular cell divisions, but also showed very large increases in plant height and leaf size suggesting a more general role for this pathway in regulating plant growth (Etchells et al., 2014). These results demonstrate that engineering PXY/CLE41 signaling offers a means to increase plant productivity in plants as diverse as the annual weed Arabidopsis to poplar trees. Project aims:1. Understand how PXY-CLE is able to regulate plant growth.2. Determine to what extent manipulating PXY-CLE signaling is able to override environmental stimuli that regulate plant growth.3. Better understand the relationship between vascular development and plant growthThis will be carried out by; 1. Looking at novel CLE signaling molecules are further able to increase plant growth.2. Examine tobacco plants with altered photosynthetic capacity in order to understand the relationship between photosynthesis, growth and vascular development. 3. Study how other pathways that increase vascular development also affect plant growth.4. Determine to what extent signals in the vascular tissue are able to override environmental growth cues.Etchells, J.P., Mishra, L., Kumar, M., Campbell, L., and Turner, S.R. (2014). "Wood Formation in Trees Is Increased by Manipulating Pxy-Regulated Cell Division". submitted. Etchells, J.P., Provost, C.M., Mishra, L., and Turner, S.R. (2013). "Wox4 and Wox14 Act Downstream of the Pxy Receptor Kinase to Regulate Plant Vascular Proliferation Independently of Any Role in Vascular Organisation". Development 140, 2224-2234. Etchells, J.P., Provost, C.M., and Turner, S.R. (2012). "Plant Vascular Cell Division Is Maintained by an Interaction between Pxy and Ethylene Signalling". PLoS Genet. 8, e1002997 Etchells, J.P., and Turner, S.R. (2010). "The Pxy-Cle41 Receptor Ligand Pair Defines a Multifunctional Pathway That Controls the Rate and Orientation of Vascular Cell Division". Development 137, 767-774.