[Exploration of cross-cultivar group characteristics of a new cultivar of Prunus mume 'Zhizhang Guhong Chongcui'].

'Zhizhang Guhong Chongcui' is a new cultivar of Prunus mume with cross-cultivar group characteristics. It has typical characteristics of cinnabar purple cultivar group and green calyx cultivar group. It has green calyx, white flower, and light purple xylem, but the mechanism remains unclear. In order to clarify the causes of its cross-cultivar group traits, the color phenotype, anthocyanin content and the expression levels of genes related to anthocyanin synthesis pathway of 'Zhizhang Guhong Chongcui', 'Yuxi Zhusha' and 'Yuxi Bian Lü'e' were determined. It was found that the red degree of petals, sepals and fresh xylem in branches was positively correlated with the total anthocyanin content. MYBɑ1, MYB1, and bHLH3 were the key transcription factor genes that affected the redness of the three cultivars of flowers and xylem. The transcription factors further promoted the high expression of structural genes F3'H, DFR, ANS and UFGT, thereby promoting the production of red traits. Combined with phenotype, anthocyanin content and qRT-PCR results, it was speculated that the white color of petals of 'Zhizhang Guhong Chongcui' were derived from the high expression of FLS, F3'5'H, LAR and ANR genes in other branches of cyanidin synthesis pathway, and the low expression of GST gene. The green color of sepals might be originated from the relatively low expression of F3'H, DFR and ANS genes. The red color of xylem might be derived from the high expression of ANS and UFGT genes. This study made a preliminary explanation for the characteristics of the cross-cultivar group of 'Zhizhang Guhong Chongcui', and provided a reference for molecular breeding of flower color and xylem color of Prunus mume.

Early changes of NLRP3 inflammasome activation after hypoxic-ischemic brain injury in neonatal rats.

The pathogenesis of neonatal hypoxic-ischemic (HI) brain injury may involve activation of the NOD-like receptor family pyrin domain-containing-3 (NLRP3) inflammasome and its downstream effectors, caspase-1 and interleukin (IL)-1ß. The start time of therapy is associated with adverse neurodevelopmental outcome following HI injury. We performed this study investigating early dynamic changes in NLRP3, caspase-1, and IL-1ß expression during the first 24 h following HI brain injury in an animal model, in order to optimize selection of treatment time after injury. Rats were randomized to an HI group (n=40) and sham group (n=40). Rats in the HI group were subjected to right common carotid artery ligation and then exposed to hypoxia (8% O2) for 2 h, and divided into 5 subgroups with 8 cases in each group at 5 postoperative time points (0, 4, 8, 12, 24 h). Brain injury during the first 24 h after surgery/hypoxia was evaluated by cranial ultrasonography. RT-PCR, western blot, and immunohistochemistry were applied to determine protein and mRNA expressions. In the HI group, ultrasonography revealed accelerated right vertebrobasilar artery flow at 4 h, enhanced brain parenchyma echogenicity at 24 h, and blood stealing from the vertebrobasilar artery at 24 h. In the HI group, immunohistochemistry demonstrated elevated expressions of NLRP3 and IL-1ß at 4, 8, 12, and 24 h and enhanced expression of caspase-1 at 8 and 12 h (all P < 0.01). Western blot and RT-PCR revealed that, compared with the sham group, the HI group exhibited elevated expression of NLRP3 at 4, 8, and 24 h, caspase-1 at 12 h, and IL-1ß at 8 h (all P < 0.05). In summary, the present results suggested that activation of NLRP3/caspase-1/IL-1ß signaling occurs within 4 h of HI brain injury in the neonatal rat.

Cryo-banking of Prunus mume pollen and its application in cross-breeding.

The Mei (Prunus mume Sieb. et Zucc.) is one of the most widely used landscape plants and important germplasm resources in China. The study of pollen cryopreservation and the construction of a pollen cryo-bank have great importance in Mei research. From 2003 to 2007 we cryopreserved pollen from 51 Mei cultivars. In vitro germination of cryopreserved pollen was not significantly different from that of fresh pollen, even after four years of storage in liquid nitrogen. Cryopreserved pollen of 19 cultivars was used successfully for intraspecific hybridizations at Wuhan and Beijing in 2005 and 2006.