6月6日,，著名學(xué)術(shù)雜志MOL. CELL. PROTEOMICS發(fā)表了北京大學(xué)生命科學(xué)學(xué)院蛋白質(zhì)工程及植物基因工程國(guó)家重點(diǎn)實(shí)驗(yàn)室朱玉賢課題組研究棉纖維伸長(zhǎng)機(jī)制的論文,。他們通過(guò)比較野生型和無(wú)長(zhǎng)絨、無(wú)短絨突變體棉花胚珠的蛋白質(zhì)組學(xué)數(shù)據(jù)發(fā)現(xiàn),，核苷糖合成途徑在棉纖維快速伸長(zhǎng)期最顯著高調(diào),，而植物激素乙烯可能通過(guò)促進(jìn)植物細(xì)胞初生壁中果膠的生物合成來(lái)調(diào)控纖維等具有線性伸長(zhǎng)機(jī)制的細(xì)胞生長(zhǎng)。
這是他們繼2006年發(fā)現(xiàn)乙烯在棉花纖維細(xì)胞伸長(zhǎng)過(guò)程中的主導(dǎo)作用（Shi et al, Plant Cell 18: 651-664）,，2007年發(fā)現(xiàn)超長(zhǎng)鏈脂肪酸位于乙烯信號(hào)上游,，在轉(zhuǎn)錄水平調(diào)控乙烯生物合成，從而影響棉纖維伸長(zhǎng)（Qin et al, Plant Cell 19: 3692-3704）后,，有關(guān)棉花等線性伸長(zhǎng)細(xì)胞生長(zhǎng)發(fā)育機(jī)制研究中的又一重要貢獻(xiàn),。(生物谷Bioon.com)
生物谷推薦原文出處：
MOL.CELL.PROTEOMICS doi: 10.1074/mcp.M110.000349
Comparative proteomics indicate that biosynthesis of pectic precursors is important for cotton fiber and Arabidopsis root hair elongation
Chao-You Pang1, Hui Wang2, Yu Pang2, Chao Xu2, Yue Jiao2, Yong-Mei Qin2, Tamara L. Western3, Shu-Xun Yu4 and Yu-Xian Zhu5,*
The quality of cotton fiber is determined by its final length and strength, which is a function of primary and secondary cell wall deposition. Using a comparative proteomics approach, we identified 104 proteins from cotton ovules 10 days post-anthesis, with 93 preferentially accumulated in the wild-type and 11 accumulated in the fuzzless-lintless mutant. Bioinformatics analysis indicated that nucleotide sugar metabolism was the most significantly up-regulated biochemical process during fiber elongation. Seven protein spots potentially involved in pectic cell wall polysaccharide biosynthesis were specifically accumulated in wild-type samples at both the protein and transcript levels. Protein and mRNA expression of these genes increased when either ethylene or lignoceric acid (C24:0) was added to the culture medium, suggesting that these compounds may promote fiber elongation by modulating the production of cell wall polymers. Quantitative analysis revealed that fiber primary cell walls contained significantly higher amounts of pectin, whereas more hemicellulose was found in ovule samples. Significant fiber growth was observed when UDP-Rha, UDP-GalA or UDP-GlcA, all of which were readily incorporated into the pectin fraction of cell wall preparations, was added to the ovule culture medium. The short root hairs of Arabidopsis uer1-1 and gae6-1 mutants were complemented either by genetic transformation of the respective cotton cDNA or by adding a specific pectin precursor to the growth medium. When two pectin precursors, produced by either UDP-4-keto-6-deoxy-D-glucose 3,5-epimerase 4-reductase or by UDP-D-glucose dehydrogenase and UDP-D-glucuronic acid 4-epimerase successively, were used in the chemical complementation assay, wild-type root hair lengths were observed in both cut1 and ein2-5 Arabidopsis seedlings, which showed defects in C24:0 biosynthesis or ethylene signaling, respectively. Our results suggest that ethylene and C24:0 may promote cotton fiber and Arabidopsis root hair growth by activating the pectin biosynthesis network, especially UDP-Rha and UDP-GalA synthesis.
