Identification of a dominant glaucous inhibitor in wheat (Iw1) and its effect on yield and senescence

如果你在清晨或下雨后穿过公园，你会注意到草地表面或树叶上有水滴。水滴倾向于从树叶上滚落，不被植物吸收，因为树叶和所有植物表面都被一层薄薄的连续层所密封，从而排斥水。这一层被称为角质层，非常重要，因为它保护植物内部(干净和潮湿)免受严酷的外部环境(肮脏和干燥)的影响。没有角质层，植物就不能在陆地上生存。角质层由一系列不同类型的蜡组成，根据所检查的植物种类而有所不同。这些不同的蜡成分极大地影响了植物与环境的相互作用，例如，通过阻止某些昆虫识别植物。它们还通过影响植物吸收或反射多少阳光来决定植物的物理属性，如植物的颜色。这一点非常重要，因为到达植物的太阳光的量决定了植物通过光合作用可以产生多少能量。对于小麦等作物，这具有重大影响，因为能源生产的增加会带来更高的谷物产量。尽管有这些明显的好处，但过量的阳光也会对植物产生负面影响。因此，角质层在植物中起着关键作用，它优化了光的捕捉，同时确保了植物的生存和繁殖。这是一项复杂的平衡行动，将根据植物生长的环境条件而改变。改良角质层蜡质成分是培育高产、适应不同环境条件的小麦品种的有效策略。这是一个重要的目标，因为我们的社会正在寻找以更少的能源和水投入生产更多粮食的方法。这一点尤其重要，因为全球变暖的威胁将在未来几十年成为现实。我们开发这些改良品种的能力将取决于我们对控制或调节小麦角质蜡成分的基因的理解，因为我们目前的知识是有限和不完整的。我们需要做得更好，而且要快。我们最近发现了小麦基因组中的一个区域，该区域影响叶和茎中沉积的角质蜡量。这个区域包含数百甚至数千个基因，但它提供了一个开始了解决定这一重要特征的遗传成分的初始切入点。有趣的是，我们还发现这一区域对谷物产量和植物的老化过程有显著影响。这些观察结果可以用两种可能的方式解释：在这个区域内有一个控制角质蜡的单一基因，它间接影响谷物产量和衰老；或者，影响这些性状的单个基因完全独立，互不相关。破译这一点很重要，这样我们才能确定这些重要特征的原因和后果。在这项建议中，我们将确定导致小麦角质层蜡质沉积变化的基因，并测试该基因在英国环境条件下是否也影响产量和植物衰老。我们还将开发使用改良角质蜡的小麦品种，并测试它们在田间条件下与未改良对照植物相比的表现。鉴定导致小麦角质蜡沉积的基因的分子性质，并测试其对产量的影响，是更好地理解和可能修改角质蜡成分的第一步，也是必不可少的一步。这将允许生产出适应性更强、产量更高的小麦品种。

If you walk through a park in the early morning or after rain has fallen you will notice drops of water on the surface of the grass or the leaves in the trees. Water drops tend to roll off the leaves and are not absorbed by the plant since leaves and all plant surfaces are sealed by a thin continuous layer that repels water. This layer, called the cuticle, is of great importance as it protects the inside of the plant (clean and humid) from the harsh external environment (dirty and dry). Without a cuticle, plants would not survive on land. The cuticle is made up of a series of different types of waxes that vary depending on the plant species examined. These different wax compositions greatly affect how the plant can interact with the environment, for example, by impeding certain insects from recognizing the plant. They also determine the physical properties of the plant, such as its color, by affecting how much sunlight is captured or reflected from the plant. This is very important as the amount of sunlight reaching the plant determines how much energy the plant can produce via photosynthesis. In crops such as wheat, this has significant implications as increases in energy production lead to higher grain yields. Despite these apparent benefits, excess sunlight can also have negative effects on the plant. Therefore, the cuticle pays a key role in the plant by optimizing light capture whilst securing its survival and reproduction. This is a complex balancing act that will change depending on the environmental conditions in which the plant is grown. A promising strategy to produce wheat varieties that can provide higher yields and adapt to different environmental conditions is to modify the cuticular wax composition. This is an important objective as our society looks for ways to produce more food with less energy and water input. This is especially relevant as the threat of global warming materializes over the next decades. Our ability to develop these improved varieties will depend on our understanding of the genes controlling or regulating cuticular wax composition in wheat as our current knowledge is limited and incomplete. We need to do better, and fast. We have recently identified a region of the wheat genome that affects the amount of cuticular wax deposited in leaves and stems. This region contains several hundred or even thousands of genes, but provides an initial entry point to start understanding the genetic components that determine this important trait. Interestingly, we also discovered that this same region has a significant effect on grain yield and on the plant's aging process. These observations could be explained in two possible ways: there is a single gene within this region controlling cuticular wax which indirectly affects grain yield and aging or alternatively, the individual genes affecting these traits are completely independent and unrelated. It is important to decipher this so that we can determine the cause and the consequences of these important traits. In this proposal we will identify the gene responsible for the change in cuticular wax deposition in wheat and test whether this gene also affects yield and plant aging under UK environmental conditions. We will also develop wheat varieties with modified cuticular wax and test how they perform under field conditions compared to unmodified control plants. Identifying the molecular nature of the gene responsible for cuticular wax deposition in wheat and testing the effects on yield is the first, but essential step, towards better understanding and possibly modifying cuticular wax composition. This will allow the production of more adaptable higher yielding wheat varieties.