The zinc-finger transcription factor BcMF20 and its orthologs in Cruciferae which are required for pollen development.

Brassica campestris Male Fertility 20 (BcMF20) is a typical zinc-finger transcription factor that was previously isolated from flower buds of Chinese cabbage (Brassica campestris ssp. chinensis). By applying expression pattern analysis, it can be known that BcMF20 was specifically and strongly expressed in tapetum and pollen, beginning from the uninucleate stage, and was maintained during the mature-pollen stage. As BcMF20 was highly conserved in Cruciferae, it can be indicated that this zinc-finger transcription factor is important during the growth of Cruciferae. In this study, 12 C2H2-type zinc-finger TFs which shared high homology with BcMF20 were found from NCBI via BLAST. A new molecular phylogenetic tree was constructed by the comparison between BcMF20 and these 12 C2H2-type zinc-finger TFs with NJ method. By analyzing this phylogenetic tree, the evolution of BcMF20 was discussed. Then, antisense RNA technology was applied in the transgenesis of Arabidopsis thaliana to get the deletion mutants of BcMF20, so that its function during the pollen development can be identified. The results showed: BcMF20 are in the same clade with three genes from Arabidopsis. The inhibition of BcMF20 expression led to smaller amounts of and lower rate in germination of pollen and lower rate in fruit setting in certain transgenetic plants. This also led to the complete collapse of pollen grains. By SEM and TEM, pollen morphology and anther development processes were observed. In the middle uninucleate microspore stage, a relatively thin or even no primexine was formed in microspores. This may result in the malformation of the pollen wall and finally cause the deformity of pollens. Above all, it can be indicated that BcMF20 may act as a part of regulation mechanisms of TAZ1 and MS1. Together they play a role in a genetic pathway in the tapetum to act on proliferation of tapetal cells and keep the normal development of pollens.

Beneficial Phytochemicals with Anti-Tumor Potential Revealed through Metabolic Profiling of New Red Pigmented Lettuces (Lactuca sativa L.).

The present study aimed to compare polyphenols among red lettuce cultivars and identify suitable cultivars for the development and utilization of healthy vegetables. Polyphenols, mineral elements, and antioxidant activity were analyzed in the leaves of six red pigmented lettuce (Lactuca sativa L.) cultivars; thereafter, we assessed the anti-tumor effects of cultivar B-2, which displayed the highest antioxidant activity. Quadrupole-Orbitrap mass spectrometry analysis revealed four classes of polyphenols in these cultivars. The composition and contents of these metabolites varied significantly among cultivars and primarily depended on leaf color. The B-2 cultivar had the highest antioxidant potential than others because it contained the highest levels of polyphenols, especially anthocyanin, flavone, and phenolic acid; furthermore, this cultivar displayed anti-tumor effects against the human lung adenocarcinoma cell line A549, human hepatoma cell line Bel7402, human cancer colorectal adenoma cell line HCT-8, and HT-29 human colon cancer cell line. Hence, the new red-leaf lettuce cultivar B-2 has a distinct metabolite profile, with high potential for development and utilization of natural phytochemical and mineral resources in lettuces and can be used as a nutrient-dense food product.