苹果果实成熟过程中ACC 合成酶基因作用机理研究进展

 苹果（Malus × domestica Borkh.）果实贮藏期的长短直接决定着其采后的经济价值，其与果实在室温下的软化率有直接的关系。乙烯能够调控苹果成熟和软化过程，因此，苹果果实软化和乙烯之间的关系得到了广泛的研究。ACC合成酶（1–氨基环丙烷–1–羧酸合成酶，ACS）是植物乙烯合成中的关键酶，通过检索苹果全基因组序列，共发现20个ACC合成酶（ACS）基因，其中MdACS1和MdACS3已经被证明与苹果果实成熟有着直接关系，并在不同的时空点调控果实成熟过程。对ACS基因调控苹果果实成熟过程的最新研究进展进行了综述，并提出了ACS基因调控苹果果实成熟和乙烯合成的分子模型，同时也对本领域今后的研究方向作了展望。

The Role of 1-aminocyclopropane-l-carboxylate Synthase Genes in Apple Fruit Ripening

AIM:To investigate the effects of the serum from rats with acute pancreatitis(AP) and tetrandrine on endocrinal and exocrinal functions of isolated rat stomachs. METHODS:Acute pancreatitis was induced in Sprague-Dawley rats by the method of retrograde bilio pancreatic duct injection with 3% sodium deoxycholate. The rat serum was collected 5 h after induction of AP, and used as an irritant to perfuse rat stomach. Endocrinal functions of the isolated rat stomachs were investigated by detecting gastrin and somatostatin in venous effluent, and exocrinal functions of the isolated rat stomachs were investigated by measuring pepsin and acid output in gastric lumen effluent. The releases of the cytokines and chemokines in venous effluent of the isolated rat stomachs were also examined. RESULTS:After induction of AP in the rats, the pancreatic tissue was damaged seriously, and obvious mucosal erosion and hemorrhages were also demonstrated in the stomach. The serum amylase level increased as well. The perfusion with AP rat serum caused significant increase in the levels of gastrin and inflammatory mediators, and decrease in the level of somatostatin in the venous effluent, and increase in the levels of pepsin and H⁺ in the gastric lumen effluent. Tetrandrine reversed the serum-induced changes, including the changes of the gastric morphology in certain degree. CONCLUSION:Toxic substances in AP serum induce injury to the endocrinal and exocrinal functions of the isolated rat stomachs. The gastroprotective and anti-inflammatory effects of tetrandrine indicates therapeutic potential for acute gastrointestinal mucosal lesions in acute pancreatitis.