Cold Temperature Regulation of Zoospore Release in Phytophthora sojae: The Genes That Differentially Expressed by Cold Temperature

Abstract

Cold temperature is an important environmental factor that affects the lives of many organisms in various ways. In this study, cold temperature was found to promote the release of zoospores from Phytophthora sojae sporangia. To better understand this phenomenon, Illumina sequencing was used to examine the differential expression of P. sojae genes between three control libraries and three cold temperature (4°C) treatment libraries. The six libraries generated 1.04, 1.17, 1.11, 0.96, 1.23, and 1.13 million clean sequencing reads. Comparison of the gene expression levels between the control and cold treatment conditions revealed 175 differentially expressed genes (DEGs), including 38 up-regulated and 137 down-regulated genes in the cold temperature group compared to the control group. The DEGs were functionally classified using the Clusters of Orthologous Groups (COG) database, and the results indicated that these DEGs were mainly involved in signal transduction, translation, ribosomal structure and biogenesis, transcription and carbohydrate transport and metabolism. KEGG pathway analysis showed that the top 20 pathways significantly enriched in DEGs included amino sugar and nucleotide sugar metabolism, arginine and proline metabolism, and starch and sucrose metabolism. Some of the DEGs are involved in the release of zoospores from P. sojae sporangia is discussed in the present work. This information will be helpful for understanding the mechanism of zoospore release induced by cold temperature.