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

世界对粮食的需求正在增长，据估计，由于世界人口的增长，产量需要增加50%才能满足不断增长的需求。这种情况因气候变化而进一步恶化，据预测，一些地区的供水量将减少，另一些地区将发生洪水。全球气温的预期上升将降低植物的生产力，并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，CO2必须通过称为气孔的可调节孔隙进入叶片，同时水通过这些孔隙损失，这也有助于冷却叶片。保持光合作用的最佳叶温很重要，因为高温会大大降低光合作用和作物产量。然而，如果失去太多的水分，植物会枯萎，最终死亡。气孔不断调整以适应不断变化的环境条件，以平衡CO2吸收和水分损失。气孔响应于增加的光而打开，然而这种响应取决于光的波长，并且通常已经鉴定出两种不同的响应。第一种被命名为“红色”光或叶肉反应。这种反应发生在强光下，与光合作用的速率直接相关;第二种是“特定的蓝色”光反应，发生在低光下，如清晨或傍晚。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的同时保持光合速率。减少用水将使持续的光合速率通过灌浆期时，水变得有限，从而提高整个周期的作物的整体光合潜力，提高粮食产量。我们将使用非转基因分蘖方法来鉴定已知在每个小麦同源物（A、B和D）中对蓝光的气孔响应（BLUS 1）至关重要的基因中的单突变，并使用这些在各种不同背景中产生单、双和三重突变体。产生的突变体将在受控环境条件和2种不同的田间环境中进行气体交换、光合生物化学和谷物产量生产的表型分析。

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.