Evolution of proteins in digestive fluid of carnivorous plants

据报道，在食肉植物的消化液中有多种酶的活性，并对编码这些酶的几个基因进行了表征，但对它们的起源和进化还没有很好的研究。我们分析了三种独立进化的猪笼草（Nepenthes alata, Sarracenia purpurea, Cephalotus follicularis）和一种紫苔（Drosera adelae）的消化液中分泌蛋白的氨基酸序列。蛋白质的相似性搜索和系统发育分析表明，非肉食性植物与液体中的蛋白质具有同源蛋白。这表明肉食性酶是从非肉食性植物中吸收的，包括发病机制和发育。

Activities of various enzymes have been reported in a digestive fluid of carnivorous plants and several genes coding the enzymes were characterized, although their origin and evolution have not been well studied. We analyzed amino acid sequences of secreted proteins in digestive fluids of three independently evolved pitcher plants Nepenthes alata, Sarracenia purpurea, and Cephalotus follicularis as well as a sundew Drosera adelae. Similarity search of the proteins and phylogenetic analyses showed that non-carnivorous plants have homologous proteins to those in the fluid. This suggests that carnivorous enzymes were co-opted from those used in non-carnivorous plants, including pathogenesis and development.