Authors: Jiandong Bao Jianqiang Yao Jinqing Zhu Weimin Hu Daguang Cai Yu Li Qingyao Shu Longjiang Fan
Publish Date: 2012/06/06
Volume: 30, Issue: 4, Pages: 1707-1714
Abstract
Waxy maize has little or very low content of amylose 5 in grain starch and carries null mutations of the waxy Wx gene With important uses as fresh maize or as an ingredient in food textile adhesive and paper industries two types of wx allele wxD7 and wxD10 had been identified In the present study 10 accessions carrying neither wxD7 nor wxD10 allele were identified from a collection of 325 waxy maize accessions The Wx locus of these 10 accessions was sequenced but no potential causative mutation was detected Further sequencing of the fulllength complementary DNAs revealed that 6 of the 10 accessions had alternative splicing patterns while the other 4 had wildtype Wx transcripts Among the six accessions one generated transcripts identical to the wxD7 allele two had the same transcripts as the wxD10 allele another two generated transcripts with deletion of the 10th and the 11th exon yet the other one produced transcripts of various lengths due to deletions from part of the 2nd exon to part of the 12th exon The wx alleles with the above alternative splicing modes are referred to as wxtD7 wxtD10 wxtD1011 and wxtD212 respectively Realtime quantitative reversetranscription polymerase chain reaction analysis of two waxy accessions that produced Wx transcripts showed significantly decreased expression having only 473 and 36 transcription level compared with B73 Sequence analysis of deletions in the transcripts with comparison with wild one showed short direct repeats at deletion endpoints similar to reported signatures of DNA deletions The waxy accessions present unique wx alleles for waxy maize breeding as well as for transcriptional regulation studies in plantsThis work was supported by the National Basic Research Program of China 2011CB109306 the Zhejiang Provincial Natural Science Foundation of China Y3080059 and the Project Based Personnel Exchange Program PPP of the China Scholarship Council and German Academic Exchange Service
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