Variations of tandem repeat, regulatory element, and promoter regions revealed by wheat-rye amphiploids.
To better understand the evolution of allopolyploids, 4 different combinations between wheat (Triticum aestivum L.) and rye (Secale cereale L.) including 12 F1 hybrids and 12 derived amphiploids were analyzed and compared with their direct parental plants by PCR analysis using 150 wheat SSR (single sequence repeat) markers and by FISH analysis using a rye-specific repetitive sequence (pSc200) as a probe. Nine SSR markers amplified rye-specific fragments whose sizes ranged from 471 bp to 1089 bp. These fragments contain regulatory elements and (or) promoters. Some of these fragments were amplified from all 24 progenies, while others were amplified from a subset of the progenies. The disappearance of rye-specific fragments from some progenies was caused by sequence elimination or DNA modification. Marker Xgwm320 amplified a new fragment (403 bp), a rye-specific tandem repeat, from some of the progenies. Twenty-eight SSR markers displayed microsatellite variation in progenies derived from 'Chinese Spring' x 'Jinzhou-heimai', but none of the 150 SSR markers displayed microsatellite variation in the progenies derived from the other three combinations. FISH signals of pSc200 were eliminated from one telomere/subtelomere of 4 chromosomes of 'Kustro' during allopolyploidization and expanded in amphiploids derived from 'Chinese Spring' x 'AR106BONE'. Thus, allopolyploidization in wheat-rye can be accompanied by rapid variation of tandem repeats, regulatory elements, and promoter regions. The alterations of repetitive sequence pSc200 indicate coordination between the constituent genomes of the newly formed amphiploids. Different genetic backgrounds of parents appear to affect genome changes during allopolyploidization.
State Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Ya'an, Sichuan 625014, China.
Zong-Xiang
ZX
Tang
Shu-Lan
SL
Fu
Zheng-Long
ZL
Ren
Jian-Ping
JP
Zhou
Ben-Ju
BJ
Yan
Huai-Qiong
HQ
Zhang
D032461:Chromosomes, Plant; D018744:DNA, Plant / Q000235:genetics; D014644:Genetic Variation; D017404:In Situ Hybridization, Fluorescence; D011003:Ploidies; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D012434:Secale / Q000235:genetics*; D020080:Tandem Repeat Sequences / Q000235:genetics*; D014908:Triticum / Q000235:genetics*
D018744:DNA, Plant