| Of the world's allocatable water resource, c.80% is currently consumed by irrigated agriculture. Along with growing populations and industrialization, as well as the phenomenon of global warming, has reduced the fresh water availability for crop plants worldwide.Howerver, the necessasity living material (foods,clothes) demands was rising along with the growing population year by year. This will require substantially more efficient production from a smaller irrigation water resource. It will require breeding crop varieties that are more efficiency in water use efficiency to maitain the world's sustainable development.Based on the previous results of Microarray analysis, a member of the LRR-RLKs family, the Populus nigra×(Populus deltoides×Populus nigra) ERECTA (PdERECTA) gene was cloned.To study the biological functions of PdERECTA, transgenic Arabidopsis plants (35S:PdERECTA) that constitutively expressed the PdERECTA gene were constructed. Overexpression of PdERECTA resulted in early seedling establishment, longer primary roots, and larger leaf areas. Notably, transgenic Arabidopsis overexpressing PdERECTA resulted in enhanced long-term water use efficiency (WUE1), as estimated by the analysis of carbon isotopic discrimination. The WUE1 results were supported by the physiological and anatomical results, which included improved photosynthetic rate, decreased transpiration rate, and stomatal density. The transgenic lines have significantly more dry-biomass as compared to the wild type.Since the overexpression of PdERECTA can strongly enhance the water use efficiency in transgenic Arabidopsis plants, PdERECTA could potentially be used in transgenic breeding to improve the water use efficiency. |
