IWYP Call 2: Manipulating stomatal blue light response in wheat to improve productivity

世界粮食需求正在增长，据估计，需要增产50%才能满足世界人口增长带来的日益增长的需求。气候变化进一步加剧了这种情况，据预测，一些地区的可用水将减少，另一些地区将发生洪水。全球气温的预期上升将降低植物生产力，增加植物对水的需求。光合作用是植物利用来自太阳的能量将大气中的二氧化碳(CO2)转化为碳水化合物和其他化合物的过程，这些化合物用于生长。光合作用发生在植物的所有绿色部分，为了使叶片光合作用发生，二氧化碳必须通过可调节的气孔进入叶片，同时水分通过这些气孔流失，这也有助于冷却叶片。保持光合作用的最佳叶温是很重要的，因为高温会大大降低光合作用和作物产量。然而，如果失去了太多的水，植物就会枯萎，最终死亡。气孔不断适应不断变化的环境条件，以平衡二氧化碳的吸收和水分的损失。气孔张开是对增加的光的反应，但是这种反应取决于光的波长，通常有两种不同的反应。第一种被称为“红色”光或叶肉反应。这种反应发生在强光下，并与光合作用的速率直接相关；第二种是“特定的蓝色”光反应，它发生在弱光下，比如清晨或傍晚的时候。降低气孔对蓝光的敏感性有可能优化作物的资源利用，从而在更有效地利用水分的同时保持光合作用速率。减少用水量将在灌浆期保持持续的光合作用速率，此时水分变得有限，从而在整个周期内增强作物的整体光合作用潜力，并提高粮食产量。我们将使用非转基因耕作方法来鉴定每个小麦同源基因(A、B和D)中一个已知在气孔对蓝光反应(BLUS1)中必不可少的基因的单突变，并使用这些突变在各种不同的背景下产生单突变、双突变和三突变。产生的突变体将在受控环境条件和两个不同的田间环境下进行气体交换、光合作用生化和粮食产量的表型鉴定。

World demand for food is growing and it has been estimated that a 50% increase in yield will be needed to meet the increasing demand due to the growing world population. This situation is further exacerbated by the changing climate, with predictions of reduced water availability in some regions and flooding in others. The anticipated increase in global temperature will reduce plant productivity as well as increase plant demands for water. Photosynthesis is the process by which plants use the energy from the sun to convert carbon dioxide (CO2) from the atmosphere into carbohydrates and other chemical compounds, which are used for growth. Photosynthesis takes place in all green parts of plants and in order for leaf photosynthesis to take place CO2 must enter the leaf through adjustable pores, called stomata, and at the same time water is lost through these pores which also aids in cooling the leaf down. It is important to maintain an optimal leaf temperature for photosynthesis, as high temperatures greatly reduce photosynthesis and crop yield. However if too much water is lost the plant will wilt and eventually die. Stomata are continually adjusting to changing environmental conditions to balance CO2 uptake with water loss. Stomata open in response to increasing light, however this response depends on the wavelength of light, and generally two different responses have been identified. The first is named the "red" light or mesophyll response. This response occurs during high light levels and is linked directly to the rates of photosynthesis; the second is the "specific blue" light response, which occurs at low light levels, such as those found early in the morning or late in the evening. Reducing stomatal sensitivity to blue light has the potential to optimise the crop's resource use, thereby maintaining photosynthetic rates while using water more efficiently. Decreasing water use will enable sustained photosynthetic rates through the grain filling period when water becomes limiting, thus enhancing overall photosynthetic potential of the crop throughout the cycle and increasing grain yield. We will use a non-transgenic tilling approach to identify single mutations in a gene known to be essential in stomatal responses to blue light (BLUS1) in each of the wheat homoeologs (A, B and D) and use these to generate single, double and triple mutants in a variety of different backgrounds. Mutants generated will be phenotyped for gas-exchange, photosynthetic biochemistry and grain yield production in both controlled environment conditions and 2 different field environments.