Molecular analysis of cuticle biosynthesis and deposition in developing sweet cherry fruit

雨致裂果是甜樱桃(Prunus avium L.)全球生产。水果容易破裂的一个主要因素是在果皮最外层，即角质膜(CM)形成的微裂缝(微裂缝)。微裂纹是由于果实快速生长阶段CM的弹性应变和塑性应变引起的，而CM沉积不足又是造成微裂纹的原因。虽然微裂纹在果实裂解中的作用已经确定，但对于甜樱桃果实中CM生物合成和沉积的分子生物学还知之甚少。本课题研究甜樱桃果实CM形成的分子遗传学。目的是了解为什么新的CM材料只在果实发育的早期交付，而不是在以后交付。具体而言，我们将1)分析果实发育过程中CM的沉积，2)识别与甜樱桃果实CM形成有关的基因，3)鉴定在果实发育早期高水平表达而在成熟果实中低水平表达的CM相关基因，4)研究CM相关基因的生物学功能。这些数据对植物CM生物学的基础研究和果树育种与生产具有重要意义。此外，它们将有助于研究其他果树的表面病害，包括葡萄浆果的裂果或苹果和其他物种的锈病。

Rain-induced fruit cracking is a serious problem in sweet cherry (Prunus avium L.) production worldwide. A major factor predisposing fruit to cracking is the formation of microscopic fractures (microcracks) in the outermost layer of the fruit skin, the cuticular membrane (CM). Microcracks result from elastic and plastic strain of the CM, which in turn is caused by inadequate CM deposition during the phase of rapid fruit growth. While the role of microcracks in fruit cracking is well established, nothing is known about the molecular biology of CM biosynthesis and deposition in sweet cherry fruit. This project investigates the molecular genetics of CM formation in sweet cherry. The aim is to understand, why new CM material is only delivered during early fruit development but not later on. In detail, we will 1) analyse CM deposition in developing fruits, 2) identify genes that contribute to CM formation in sweet cherry fruits, 3) identify CM-related genes that are expressed at high levels early in fruit development and at low levels in maturing fruits, and 4) investigate the biological functions of CM-related genes. The data obtained are relevant for both the basic research of plant CM biology, and for fruit crop breeding and production. Furthermore, they will be useful in studying surface disorders in other fruit crops including cracking of grape berry or russeting in apple and other species.