Cloning and expression of the EsxA gene and the growth-promoting effects of the encoded protein on rice seedlings.

An EsxA-encoding gene (esxA) was previously identified in the genome of the plant growth-promoting rhizobacterium Paenibacillus terrae strain NK3-4. The esxA was cloned and expressed in Pichia pastoris, after which the effects of the EsxA protein on rice seedling growth were analyzed to determine whether EsxA contributes to the plant growth-promoting activity of strain NK3-4. The esxA was successfully cloned from the NK3-4 genome and ligated to the eukaryotic expression vector pPICZαA. The resulting pPICZαA-esxA recombinant plasmid was transinfected into yeast cells, and esxA expression in the yeast cells was confirmed. The treatment of seed- buds with the EsxA protein increased the root length by 1.35-times, but decreased the bud length. Additionally, in rice seedlings treated with EsxA, the root and shoot lengths increased by 2.6- and 1.7-times, respectively. These findings imply that EsxA is important for the promotion of rice plant growth by P. terrae strain NK3-4. Furthermore, the construction of the esxA expression vector and the engineered strain may be useful for future investigations of the mechanism underlying the plant growth-promoting effects of EsxA, with implications for the application of EsxA for regulating plant growth.

Tissue distribution and expression of signaling lymphocyte activation molecule receptor to peste des petits ruminant virus in goats detected by real-time PCR.

In the present study, we investigated the tissue distribution and expression of signaling lymphocyte activation molecule (SLAM) in 40 tissues and organs of goats by real-time RT-PCR, in order to determine the role of these receptors in tissue tropism. SLAM mRNA was detected in all the samples investigated. The expression of SLAM mRNA was detected at high levels in spleen, mesenteric lymph node, hilar lymph node, mandibular lymph node, superficial cervical lymph node, nasal mucosa, duodenum, heart, gallbladder, thymus and blood; this is similar to the tissue tropism of peste des petits ruminant virus. However, it was surprising that expression of SLAM was low in lungs, colon and rectum which are the major sites of replication of PPRV. In addition, very low levels were detected in larynx, tongue and esophagus, which suggest the possible presence of an alternative receptor for PPRV. This study provided the first data on caprine SLAM for use in further studies of the pathogenesis of PPRV in goats.