Qsw5

Function

The biological function of gene Qsw5 is that it through increasing the number of cells in rice flowers lemma,then increaseing the capacity of rice husk, and ultimately increase the grain width.Pets the gene loci of  Kasalath qSW5,  the grain width lines into smaller, field production decreased by 10%.But through the gene RNAi regulate ORF1's expression down  (ORF1 is one sets of Kasalath qSW5) ,then can make larger grain width and increase output.Therefore, loss of function qSW5 sites have value in breeding.

Expression Qsw5 can be involved in the expression of rice seed colors . Variation in the colors of the rice seed pericarp of the previous ‘heritage landraces’. These landraces retain all functional alleles of three domestication-related genes (qSW5, Wx and qSH1) at the three FNP positions (Shomura et al. 2008). Use japonica rice Nipponbare with indica rice Kasalath hybrid to biuld F2 population,In the fifth chromosome location to a control grain width of main effect QTL, it ie the Qsw5.Through positional cloning puting qSW5 finly positioning into 2263 bp, Finally,through gene expression analysis, and a complementary experiment to determine which one ORF (open reading frame) of qSW5. Qsw5 can be involved in the expression of rice seed width. Evolution By combining qSW5, wx and qSH1 variation of these three genes form the current "Nipponbare." Rice seed size is an important agronomic trait in determining the yield potential, and four seed size related genes (GS3, GW2, qSW5/GW5 and GIF1) have been cloned in rice so far. However, the relationship among these four genes is still unclear, which will impede the process of gene pyramiding breeding program to some extent. To shade light on the relationship of above four genes, gene expression analysis was performed with GS3-RNAi, GW2-RNAi lines and CSSL of qSW5 at the transcriptional level. The results clearly showed that qSW5 and GW2 positively regulate the expression of GS3. Meanwhile, qSW5 can be down-regulated by repression of GW2 transcription. Additionally, GIF1 expression was found to be positively regulated by qSW5 but negatively by GW2 and GS3. Moreover, the allelic effects of qSW5 and GS3 were detailedly characterized based on a natural population consisting of 180 rice cultivars. It was indicated that mutual interactions exist between the two genes, in which, qSW5 affecting seed length is masked by GS3 alleles, and GS3 affecting seed width is masked by qSW5 alleles. These findings provide more insights into the molecular mechanisms underlying seed size development in rice and are likely to be useful for improving rice grain yield. [1]. Alonso-Blanco C, Aarts MG, Bentsink L, Keurentjes JJ, Reymond M, Vreugdenhil D, et al. What has natural variation taught us about plant development, physiology, and adaptation?[J]. The Plant cell. 2009,21(7):1877-96. [2]. Kitagawa K, Kurinami S, Oki K, Abe Y, Ando T, Kono I, et al. A novel kinesin 13 protein regulating rice seed length[J]. Plant & cell physiology. 2010,51(8):1315-29. [3]. Konishi S, Ebana K, Izawa T. Inference of the japonica rice domestication process from the distribution of six functional nucleotide polymorphisms of domestication-related genes in various landraces and modern cultivars[J]. Plant & cell physiology. 2008,49(9):1283-93. [4]. Tanabata T, Shibaya T, Hori K, Ebana K, Yano M. SmartGrain: high-throughput phenotyping software for measuring seed shape through image analysis[J]. Plant physiology. 2012,160(4):1871-80.