Long-Term Animal Feeding Trial of the Refined Konjac Meal Ⅰ. Effects of the Refined Konjac Meal on the Calcium and Phosphorus Metabolism and the Bone in Rat

Effects of refined konjac meal (RKM) on the calcium and phosphorus metabolism and bone parameters were observed in rats of both sexes fed with food containing 1% of RKM for 18 months. A comparable group of rats fed on basic diet only was used as a control.Results obtained indicate that all the measured parameters (serum calcium and phosphorus level, femur weight and its calcium and phesphorus content, and the osteometry of the tibia) showed no significant difference between the experimental and the control groups.Thus there is no adverse effect either on the calcium and phosphorus metabolism or on the bone after a long-term intake at a moderate dosage.

Natural variation in ZmGRF10 regulates tolerance to phosphate deficiency in maize by modulating phosphorus remobilization

Phosphorus is a limiting factor in agriculture due to restricted availability in soil and low utilization efficiency of crops.The identification of superior haplotypes of key genes responsible for low-phosphate(Pi)tolerance and their natural variation is important for molecular breeding.In this study,we conducted genome-wide association studies on low-phosphate tolerance coefficients using 152 maize inbred lines,and identified a significant association between SNPs on chromosome 7 and a low-phosphate tolerance coefficient.ZmGRF10 was identified as a candidate gene involved in adaptation of maize to Pi starvation.Expression of ZmGRF10 is induced by Pi starvation.A mutation in ZmGRF10 alleviated Pi starvation stress.RNA-seq analyses revealed significant upregulation of genes encoding various phosphatases in the zmgrf10-1 mutant,suggesting that ZmGRF10 negatively regulates expression of these genes,thereby affecting low-Pi tolerance by suppressing phosphorus remobilization.A superior haplotype with variations in the promoter region exhibited lower transcription activity of ZmGRF10.Our study unveiled a novel gene contributing to tolerance to low-Pi availability with potential to benefit molecular breeding for high Pi utilization.

Identification,characterization,and verification of miR399 target gene in grape

The microRNA miR399 plays an important role in phosphorus signal transduction pathways in plants.Previously,miR399 was shown to be closely associated with berry ripening in grape(Vitis vinifera).The objective of the present study was to elucidate the evolutionary characteristics of the miR399 gene family in grape and to verify the cleavage effect on the target genes.Grape miR399s were identified by miRNA sequencing and retrieval from the miRBase database.The mature sequences and precursor sequences were subjected to phylogenetic analysis to reconstruct evolutionary trees,as well as secondary structure analysis of the precursor sequence,and prediction of target genes.The cisacting elements in the miR399 promoter were predicted and the cleavage effect of grape miR399b on its target genes was verified.The grape miR399 family comprised nine precursor sequences and nine mature sequences.The precursor sequences formed a typical and stable stem—loop structure.The minimum folding free energy ranged from-55.70 kcal·mol^(-1)to-37.40 kcal·mol^(-1).Multiple sequence alignment revealed that the miR399 family was highly conserved.The grape miR399 family was phylogenetically closely related to peach,apple,and citrus miR399s.Grape miR399s were predicted to target inorganic phosphate transporter 1—3,phospholipase D delta-like,and beta-glucuronosyltransferase.The cleavage effect of grape miR399b on the target genes was verified by means of a dual-luciferase assay and 5’RLM-RACE.Histochemical GUS staining showed that the promoter activity of miR399b was promoted by GA3treatment.

Research Progresses on Physiological Functions of Vitamin D

Vitamin D is a fat soluble vitamin that is foundin a variety of forms , amongwhich 1,25-（0H） 2D3 is themain active form. It not only exhibits a major physiological function to regulate the metabolism of calcium and phosphorus, but also relates to the prevention and treatment of a variety of diseases such as lung diseases, cancers, diabetes, tuberculosis, lupus erythematosus, autoimmune diseases and liver damage. In this paper, the latest research progresses of the physiological function of vitamin D were summarized and discussed, aiming at providing the solid basis for utilization and application of vitamin D.