Cell specific expression of genes in C4 photosynthesis

到2050年，由于人口增长，我们至少需要比今天多50%的食物。然而，水稻等作物的最高产量却停滞不前。很少有生物学先例表明产量可以增加这个数量级，但C4光合作用是其中之一。因此，有人提出，应该尝试将C4光合作用的特性植入目前使用效率较低的C3途径的作物中。在这是可行的之前，我们需要更好地了解C4途径是如何运作的。我们最近发现了一个由多个基因共享的区域，该区域在C4植物C.gynandra的叶片中产生BS特异性。这是第一个由编码区内的信息产生的C4叶细胞特异性的例子。此外，该区域已经存在于C3物种的同源基因中，因此表明基因可以直接招募到C4叶片的细胞特异性表达中，而不需要改变序列。我们的目标是定义该区域中存在的产生BS专一性的核苷酸，确定C4循环中其他基因在多大程度上受到其编码区内元素的调控，以及C3物种的基因已经在多大程度上拥有在C4叶片中产生M或BS专一性的元素。

By 2050, due to population growth we will need at least 50% more food than today. However, increases in the maximum yield of crops such as rice have plateaued. There are few biological precedents that show that yields can be increased by this order of magnitude, but C4 photosynthesis is one of them. It has therefore been proposed that placing characteristics of C4 photosynthesis into crops that currently use the less efficient C3 pathway should be attempted. Before this is feasible, we need a better basic understanding of how the C4 pathway operates. We have recently identified a region that is shared by multiple genes, and that generates BS specificity in leaves of the C4 plant C. gynandra. This is the first example of cell specificity in C4 leaves being generated by information within coding regions. In addition, this region is already present in orthologous genes from C3 species, and so shows that genes can be directly recruited into cell specific expression in C4 leaves without any change in sequence. We aim to define the nucleotides present in this region that generate BS specificity, to determine the extent to which other genes in the C4 cycle are regulated by elements within their coding regions, and also to define the extent to which genes from C3 species already possess elements that generate M or BS specificity in C4 leaves.