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，我们正在进入一个地球仪大部分地区更频繁地暴露于极端和多变天气的时期。虽然这些变化对植物生长模式的影响尚不清楚，但提高生产力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，以及在何种程度上可以操纵它，以提高生产力，即使在面对波动或不利的环境条件。在一年生植物拟南芥中，我们已经鉴定了肽配体CLE 41和受体激酶PXY之间的信号传导控制形成层细胞分裂，并且已经证明操纵该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年）。最近，我们已经能够证明，改变CLE 41和PXY的白杨同源物的表达增加形成层细胞分裂，这表明该途径在树木径向生长的进化中发挥着重要作用。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分裂，而且还显示出植物高度和叶大小的非常大的增加，这表明该途径在调节植物生长中的更普遍的作用（Etchells等人，2014）。这些结果表明，工程PXY/CLE 41信号提供了一种手段，以增加植物的植物生产力，从一年生杂草拟南芥到白杨。项目目标：1.了解PXY-CLE如何调节植物生长。2.确定在何种程度上操纵PXY-CLE信号能够覆盖调节植物生长的环境刺激。更好地了解维管发育和植物生长之间的关系这将通过以下方式进行：1.展望新型CLE信号分子能够进一步促进植物生长.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.研究增加维管发育的其他途径如何也影响植物生长。确定血管组织中的信号在多大程度上能够覆盖环境生长线索。米什拉湖Kumar，M.，坎贝尔湖，和Turner，S.R.（2014年）。“树木中的木材形成通过操纵Pxy调节的细胞分裂增加”。已提交。Etchells，J.P.，教务长C.M.米什拉湖和Turner，S.R.（2013年）。Wox 4和Wox 14在Pxy受体激酶的下游起作用，以独立于血管组织中的任何作用调节植物血管增殖。发展140，2224-2234。Etchells，J.P.，教务长C.M.和Turner，S.R.（2012年）。植物维管细胞分裂是由Pxy和乙烯信号之间的相互作用维持的。PLoS基因组8，e1002997 Etchells，J.P.，和Turner，S.R.（2010年）。Pxy-Cle41 Receptor Ligand Pair Defines a Multifunctional Pathway That Controls the Rate and Orientation of Vascular Cell Division.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.