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[優(yōu)秀文章推薦] 中大在miRNA介導(dǎo)藍(lán)銅蛋白調(diào)控水稻產(chǎn)量研究中取得新進(jìn)展
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![[優(yōu)秀文章推薦] 中大在miRNA介導(dǎo)藍(lán)銅蛋白調(diào)控水稻產(chǎn)量研究中取得新進(jìn)展]()
該研究通過系統(tǒng)的形態(tài)學(xué)和細(xì)胞學(xué)觀察結(jié)合分子生物學(xué)手段,揭示了miR408靶向藍(lán)銅蛋白編碼基因OsUCL8可以影響葉綠體內(nèi)銅離子穩(wěn)態(tài),進(jìn)而導(dǎo)致水稻光合速率增強(qiáng)、產(chǎn)量增高。
中山大學(xué)陳月琴教授團(tuán)隊(duì)于2013年發(fā)現(xiàn)并報(bào)道了第一例正向調(diào)節(jié)水稻產(chǎn)量的miRNA--miR397(Nature Biotechnology, 2013)。在此基礎(chǔ)上,通過miRNA表達(dá)模式和靶基因功能分析,篩選獲得第二例正調(diào)控水稻產(chǎn)量的miRNA分子--miR408。MiR408通過調(diào)控藍(lán)銅蛋白編碼基因OsUCL8影響植株的光合作用效率以及產(chǎn)量性狀等。
![[優(yōu)秀文章推薦] 中大在miRNA介導(dǎo)藍(lán)銅蛋白調(diào)控水稻產(chǎn)量研究中取得新進(jìn)展-1]()
銅是生物體不可或缺的金屬元素之一,由其參與構(gòu)成的銅蛋白廣泛存在于動物、植物和微生物中。銅蛋白具有多種生理功能,包括載氧、銅庫貯存、電子傳遞和氧化還原等。在植物藍(lán)銅蛋白中最為著名的當(dāng)數(shù)光合電子傳遞鏈上的質(zhì)體藍(lán)素(plastocyanin)。在該研究中,研究者發(fā)現(xiàn)miR408過表達(dá)可以導(dǎo)致水稻產(chǎn)量增高,而其靶基因OsUCL8的CRISPR敲除或RNAi敲低植株也表現(xiàn)出與miR408過表達(dá)相一致的表型。研究表明,細(xì)胞質(zhì)定位的藍(lán)銅蛋白OsUCL8會影響植物細(xì)胞總銅含量和葉綠體銅庫,導(dǎo)致葉綠體內(nèi)質(zhì)體藍(lán)素的穩(wěn)定性發(fā)生變化,進(jìn)而改變植株的光合作用效率以及株型、穗型、粒型等產(chǎn)量性狀。
![[優(yōu)秀文章推薦] 中大在miRNA介導(dǎo)藍(lán)銅蛋白調(diào)控水稻產(chǎn)量研究中取得新進(jìn)展-2]()
Increasing grain yield is the most important subject of crop breeding. Here, we report the elevated expression of a conserved microRNA, OsmiR408, could positively regulate grain yield in rice by increasing panicle branches and grain number. We further showed that OsmiR408 regulates grain yield by downregulating its downstream target, OsUCL8, which is an uclacyanin (UCL) gene of the phytocyanin family. The knock down or knock out of OsUCL8 also increases grain yield, while the overexpression of OsUCL8 results in an opposite phenotype. Spatial and temporal expression analyses showed that OsUCL8 was highly expressed in pistils, young panicles, developing seeds and inflorescence meristem, and was nearly complementary to that of OsmiR408. Interestingly, the OsUCL8 protein was localized to the cytoplasm, distinctive from a majority of phytocyanins which localize to the plasma membrane. Further studies revealed that the cleavage of OsUCL8 by miR408 affects copper homeostasis in the plant cell, which in turn affects the abundance of plastocyanin proteins and photosynthesis in rice. This is the first report of the effects of miR408-OsUCL8 in regulating rice photosynthesis and grain yield. Our study further broadens the perspective of miRNAs and UCLs and provides important information for breeding high-yielded crops through genetic engineering. |
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