Xinjiang rice wheat (
Udacz. et Migush, 2n=6x=42, AABBDD) is one of the endemic Chinese wheats, only distributing in Xinjiang and Xizang (Tibet), China. A novel high-molecular-weight (HMW) glutenin subunit gene
was isolated and characterized from Xinjiang rice wheat accession Daomai2. The complete open reading frame (ORF) of
is 2508 bp, encoding 836 amino acids. The primary structure of 1Dx2.1 consists of three distinct domains, a non-repetitive N-terminal domain with 89 residues, a non-repetitive C-terminal domain with 42 residues and a large central repetitive domain with 684 residues. In the N-terminal of 1Dx2.1, there is an R (arginine) at position 75, whereas there is a Q (glutamine) in other known x-type subunits. Four cysteine residues are observed in 1Dx2.1 with three in the N-terminal region and one in the C-terminal region. The number and distribution of cysteines in 1Dx2.1 are identical to those in x-type subunits except for 1Dx5, which possesses an extra cysteine residue. Differences between the repetitive domain of 1Dx2.1 and those of known HMW subunits resulted from substitutions, insertions or/and deletions involving single or more amino acid residues. The phylogenetic tree, which was constructed on the basis of amino acid sequences, and indicated that 1Dx2.1 was highly related to 1Dx2.1
, then to 1Dx2 and 1Dx5.
Authors:N. Li, Z. Yu, L. Wang, Y. Zheng, J. Jia, Q. Wang, M. Zhu, X. Liu, X. Xia, and W. Li
The aim of this study was to investigate the effects of maternal lead exposure on the learning and memory ability and expression of tau protein phosphorylation (P-tau) and beta amyloid protein (Aβ) in hippocampus of mice offspring. Pb exposure initiated from beginning of gestation to weaning. Pb acetate administered in drinking solutions was dissolved in distilled deionized water at the concentrations of 0.1%, 0.5% and 1% groups. On the 21
of postnatal day, the learning and memory ability of the mouse pups was tested by Water Maze test and the Pb levels in blood and hippocampus of the offspring were also determined. The expression of P-tau and Aβ in hippocampus was measured by immunohistochemistry and Western blotting. The Pb levels in blood and hippocampus of all exposure groups were significantly higher than that of the control group (
< 0.05). In Water Maze test, the performances of 0.5% and 1% groups were worse than that of the control group (
< 0.05). The expression of P-tau and Aβ was increased in Pb exposed groups than that of the control group (
< 0.05). Tau hyper-phosphorylation and Aβ increase in the hippocampus of pups may contribute to the impairment of learning and memory associated with maternal Pb exposure.
Authors:Y.P. Jing, D.T. Liu, X.R. Yu, F. Xiong, D.L. Li, Y.K. Zheng, Y.F. Hao, Y.J. Gu, and Z. Wang
The objective of the present study was to understand the developmental regularity of wheat endosperm cells at different Days After Pollination (DAP) using microscopic and histochemical methods. Resin semi-thin sections of the endosperm and the enzymatically dissociated Starchy Endosperm Cells (SECs) were observed under a light microscope. The results showed that: (1) SECs were irregular-shaped and had two types of starch granules: large oval-shaped A-type starch granules and small spherical B-type starch granules. (2) The growth shape of SECs was referred to as S-curve and the fastest cell growth period was at 16–24 DAP. (3) The largest increase and growth of A-type starch granules were mainly at 4–16 DAP. B-type starch granules increased rapidly after 16 DAP and made up over 90% of the total starch granules in SEC during the late stage of endosperm development. (4) The nuclei of SEC deformed and degenerated during the middle and late stages of endosperm development and eventually disappeared. However, starch granules still increased and grew after the cell nuclei had degenerated. The investigations showed the development regularity of starch endosperm cells and starch granules, thereby improving the understanding of wheat endosperm development.