McGaughey Samantha A, Osborn Hannah L, Chen Lily, Pegler Joseph L, Tyerman Stephen D, Furbank Robert T, Byrt Caitlin S, Grof Christopher P L
Centre for Plant Science, School of Environmental and Life Sciences, University of Newcastle, CallaghanNSW, Australia; Australian Research Council Centre of Excellence in Plant Energy Biology, Waite Research Institute and School of Agriculture, Food and Wine, University of Adelaide, Glen OsmondSA, Australia.
Australian Research Council Centre of Excellence for Translational Photosynthesis, College of Medicine, Biology and Environment, Australian National University, Canberra ACT, Australia.
Front Plant Sci. 2016 Dec 1;7:1815. doi: 10.3389/fpls.2016.01815. eCollection 2016.
is a C grass used as a model for bioenergy feedstocks. The elongating internodes in developing stems grow from an intercalary meristem at the base, and progress acropetally toward fully expanded cells that store sugar. During stem development and maturation, water flow is a driver of cell expansion and sugar delivery. As aquaporin proteins are implicated in regulating water flow, we analyzed elongating and mature internode transcriptomes to identify putative aquaporin encoding genes that had particularly high transcript levels during the distinct stages of internode cell expansion and maturation. We observed that was highly expressed in internode regions undergoing cell expansion, and was highly expressed in mature sugar accumulating regions. Gene co-expression analysis revealed expression was highly correlated with the expression of five putative sugar transporters expressed in the internode. To explore the function of the proteins encoded by and , we expressed them in oocytes and tested their permeability to water. SvPIP2;1 and SvNIP2;2 functioned as water channels in oocytes and their permeability was gated by pH. Our results indicate that SvPIP2;1 may function as a water channel in developing stems undergoing cell expansion and SvNIP2;2 is a candidate for retrieving water and possibly a yet to be determined solute from mature internodes. Future research will investigate whether changing the function of these proteins influences stem growth and sugar yield in .
是一种用作生物能源原料模型的C类草。发育中的茎中伸长的节间从基部的居间分生组织生长，并向顶端朝着储存糖分的完全膨胀细胞推进。在茎的发育和成熟过程中，水流是细胞扩张和糖分输送的驱动力。由于水通道蛋白与调节水流有关，我们分析了伸长和成熟节间的转录组，以鉴定在节间细胞扩张和成熟的不同阶段具有特别高转录水平的假定水通道蛋白编码基因。我们观察到在经历细胞扩张的节间区域中高表达，并且在成熟的糖分积累区域中高表达。基因共表达分析表明，的表达与在节间表达的五个假定糖转运蛋白的表达高度相关。为了探索和编码的蛋白质的功能，我们在卵母细胞中表达它们并测试它们对水的通透性。SvPIP2;1和SvNIP2;2在卵母细胞中作为水通道起作用，并且它们的通透性受pH调节。我们的结果表明，SvPIP2;1可能在经历细胞扩张的发育中的茎中作为水通道起作用，并且SvNIP2;2是从成熟节间回收水分以及可能回收尚未确定的溶质的候选者。未来的研究将调查改变这些蛋白质的功能是否会影响的茎生长和糖分产量。
