WRKY transcription factors are one of the largest families in plants, playing important roles in regulating plant immunity. Malus sievesii has abundant genetic diversity and can offer various and high-quality gene resources. In this study, 112 putative MsWRKY proteins were identified from a full-length transcriptome of M. sieversii during the Valsa canker disease (caused by Valsa mali). The MsWRKY proteins were phylogenetically divided into three groups (I–III). Motif compositions of the MsWRKY proteins were clustered and fifteen conserved motifs were observed. Expression pattern analysis showed that thirty-four MsWRKY transcripts strongly responded to the V. mali infection, demonstrating that MsWRKY transcripts might play different roles during the response. Functional identifications were subsequently conducted with transient expressions, demonstrating that MsWRKY16, MsWRKY21, MsWRKY70, MsWRKY74 and MsWRKY85 positively regulated the resistant response. Besides, the MsWRKY21, MsWRKY70 and MsWRKY85 were dramatically induced by salicylic acid (SA), methyl-jasmonate acid (MeJA) and 1-aminocyclopropane-1-carboxylate (ACC), indicating that they play important roles in the regulatory resistance of V. mali infection. This work provides a comprehensive understanding of the WRKY family in M. sieversii and will build a foundation for future research of the potential disease resistances MsWRKY transcripts.

Data on sessilinasis from Procambarus clarkia are limited. This study investigates sessilid diversity in Hubei Province, China in 2016. Procambarus clarkia pereopods were covered by two sessilid morphotypes in April and May, and the gills were adhered by one of these two morphotypes (morphotype I) in January. Identifying the two morphotypes according to their morphological characters through live observations and protargol-stained method is difficult. Both morphotypes show almost identical morphological characteristics: zooids present vase-shaped, the length-to-width ratio is 2:1, the semicircle-shaped peristomial disk is evidently above the peristomial lip, single contractile vacuole is located below the peristomial lip, and the oral infraciliature shows identical arrangement which can be distinguished from other Epistylis. However, the morphometric data of the two morphotypes are significant different: body size of morphotype I is 78.9-103.8 × 32.1-54.6 μm, whereas that of morphotypes II is 136.7-171.5 × 60.9-88.0 μm. To further identify the two morphotypes, molecular regions including small subunit ribosomal DNA (SSU rDNA) sequences, large subunit ribosomal DNA (LSU rDNA) sequences, and ITS1-5.8S-ITS2 sequences were used. Results supported that the two morphotypes are single species of genus Epistylis rather than distinct species based in their distinct size ranges and temporal presence events. We assigned it the name E. semiciculus n. sp. with respect to the semicircular peristomial disk. Overall, these findings emphasized the importance of using molecular data to solve the identification confusion caused by ontogenetic processes. This study is the first morphological and molecular characterization of a sessilid isolated from P. clarkia under aquaculture conditions.