Os07g0153600

PROG1(PROSTRATE GROWTH 1),a semi-dominant gene controls aspects of wild-rice plant architecture, including tiller angle and number of tillers.

Function

PROG1 variants identified in O. sativa disrupt the prog1 function and inactivate prog1 expression, leading to erect growth, greater grain number and higher grain yield in cultivated rice. Sequence comparison shows that 182 varieties of cultivated rice, including 87 indica and 95 japonica cultivars from 17 countries, carry identical mutations in the prog1 coding region that may have become fixed during rice domestication.

In the process of the evolution of the rice, wild rice by PROG1 genetic evolution of cultivated rice PROG1, gene function is lost, not only by the creeping growth to erect, be modified to improve plant type, and spike grain number increase, the yield increased significantly, and performance for sex. By sequence analysis found that 182 rice varieties from 17 countries of prog1 gene expression of the same variation, indicate that the genes may be the origin of the single.PROG1 gene detection and separation to reveal the molecular mechanism of rice evolution and study the molecular basis of rice plant type regulation is of great significance to (Tan et al., 2008).

Here some experiments to find the function of PROG1. They further developed a near-isogenic line, NIL(PROG1), that contained a very short PROG1chromosomal segment from wild rice in the Teqing genetic background and characterized the plant architecture (Fig. 1). During the early seedling stage, both tiller bud formation and tiller outgrowth in NIL(PROG1) were earlier than that in Teqing (Fig. 1a,b). After the tillering stage, NIL(PROG1)produced many tillers, but Teqing produced very few (Fig. 1c,d,f). Furthermore, NIL(PROG1) showed increased tiller spread with a wider tiller angle, whereas Teqing had a compact plant architecture with a narrower tiller angle (Fig. 1c,e). These results show that NIL(PROG1) possesses plant architecture similar to that of wild rice, including a prostrate growth (a wider tiller angle) and many tillers, suggesting that PROG1 may be a key domestication gene responsible for plant architecture.(Jin et al., 2008).

Localization

PROG1 (PROSTRATE GROWTH 1), on chromosome 7 that encodes a single Cys2-His2 zinc-finger protein.

Genetic linkage analysis within 246 F2individuals derived from the cross between YIL18 and Teqing showed that prostrate growth was completely associated with a marked decrease of GNP and controlled by a single semi-dominant gene,PROG1(PROSTATE GROWTH 1), located between SSR markers RM298 and RM481 on short arm of chromosome 7 (Fig. 3a). Using a total of 3,600 recessive homozygote plants with erect growth from the F2population, we further delimited prog1 within an 8.8-kb region between the pr5 and pr7 markers (Fig. 3b). Within this region, there is only one hypothetical gene (LOC_Os07g05900) in the Nipponbare genome (the TIGR Rice Genome Annotation Database)9 (Fig. 3c). One positive BAC clone (YJ0710308) covering this region was isolated from genomic BAC library of YJCWR (Fig. 3d). We screened the YJ0710308 subclone library and identified two subclones, pPROG1-1 and pPROG1-2, containing the entire O. rufipogonLOC_Os07g05900 with 596-bp and 2,914-bp 5¢-flanking regions, respectively (Fig. 3e)(Jin et al., 2008).

PROG1 (PROSTRATE GROWTH 1), located in the rice chromosome 7 short arm SSR markers between RM298 and RM481 (Tan et al., 2008);Also between mark S1706 and RM7185 (Jin et al., 2008).Two independent team used two kinds of rice hybridization and introgression, after repeated increase of genetic map, they successfully separation and cloned gene PROG1.

PROG1 cDNA 833 bp and contains a 486 - bp open reading frame (ORF), 147 - bp's 5 'end the translation section (untranslated region, UTR) and 200 - bp 3' UTR, encoding a 161 amino acid composition of Cys2 - His2 zinc finger protein (Tan et al., 2008). PROG1 encoding a 167 amino acid composition of zinc finger transcription factors, mainly in the axillary bud separatist group.In the gene encoding between wild rice and cultivated rice in hainan area has a base mutation amino acid replacement, speculated that the amino acid substitution in the process of artificial domestication is selected (Jin et al., 2008).

Expression

PROG1 is predominantly expressed in the axillary meristems, the site of tiller bud formation. Rice transformation experiments demonstrate that artificial selection of an amino acid substitution in the PROG1 protein during domestication led to the transition from the plant architecture of wild rice(O.rufipogon) to that of domesticated rice(O.sativa).

References

1. Lubin Tan;Xianran Li;Fengxia Liu;Xianyou Sun;Chenggang Li;Zuofeng Zhu;Yongcai Fu;Hongwei Cai;Xiangkun Wang;Daoxin Xie;Chuanqing Sun

 Control of a key transition from prostrate to erect growth in rice domestication
 Nature Genetics, 2008, 40(11): 1360-1364

2. Jian Jin;Wei Huang;Ji-Ping Gao;Jun Yang;Min Shi;Mei-Zhen Zhu;Da Luo;Hong-Xuan Lin

 Genetic control of rice plant architecture under domestication
 Nature Genetics, 2008, 40(11): 1365-1369

3. Yonghong Wang & Jiayang Li

 Rice, rising
 Nature Genetics, 2008, 40(11): 1273-1275

Structured Information

(a) Amino acid sequence alignments of the zinc finger domain. Identical residues are shown in colored boxes. Asterisks indicate cysteine and histidine in C2H2-type zinc finger domain. (b) Comparison of the 2.679-kb sequence between Teqing and wild rice revealed six mutations (M1–M6). Two and four mutations are located in the ORF (shown by box) and promoter region of the PROG1, respectively. Five mutations are 1-bp substitutions, and one is a 2-bp deletion (M4) in the promoter region of wild-rice PROG1 (2.677-kb sequences for the wild rice).