The qSD12 underlying gene promotes abscisic acid accumulation in early developing seeds to induce primary dormancy in rice聽聽 [涓嬭浇]

<缇庡浗鍗楄揪绉戝宸炵珛澶у妞嶇墿绉戝璇曢獙瀹�>

ABA鍦ㄨ瀵间紤鐪犱腑璧烽噸瑕佷綔鐢ㄣ�俼SD12鏄互鍓嶅湪鏉傝崏绋讳腑妫�娴嬪埌鐨勪紤鐪燪TL锛岃繖绡囨枃绔犵簿缁嗗畾浣嶈嚦75kb锛�9涓娴嬪熀鍥狅紝鍏朵腑涓�涓狿IL5鍜宐HLH杞綍瀛愭槸鍙兘鍩哄洜銆傚埄鐢ㄦ潅鑽夌ɑBac搴撴悶浜嗚繎绛夊熀鍥犵郴锛屽彂鐜伴珮浼戠湢绯荤瀛�10澶╂椂鍊欑殑ABA鍚噺瓒呰繃鍙﹀涓�涓�傝繖娈靛尯闂存病鏈夎窡ABA鐩存帴鐩稿叧鐨勫熀鍥狅紝鎵�浠ユ悶浜嗕簺鐚滄祴鐨勪笢瑗库�︹��

Seeds acquire primary dormancy during their development and the phytohormone abscisic acid (ABA) is known to play a role in inducing the dormancy. qSD12 is a major seed dormancy quantitative trait locus (QTL) identified from weedy rice. This research was conducted to identify qSD12 candidate genes, isolate the candidates from weedy rice, and determine the relation of the dormancy gene to ABA. A fine mapping experiment, followed by marker-assisted progeny testing for selected recombinants, narrowed down qSD12 to a genomic region of <75 kb, where there are nine predicted genes including a cluster of six transposon/retrotransposon protein genes and three putative (a PIL5, a hypothetic protein, and a bHLH transcription factor) genes based on the annotated Nipponbare genome sequence. The PIL5 and bHLH genes are more likely to be the QTL candidate genes. A bacterial artificial chromosome (BAC) library equivalent to 8-9 times of the haploid genome size was constructed for the weedy rice. One of the two BAC contigs developed from the library covers the PIL5 to bHLH interval. A pair of lines different only in the QTL-containing region of <200 kb was developed as isogenic lines for the qSD12 dormancy and non-dormancy alleles. The dormant line accumulated much higher ABA in 10-day developing seeds than the non-dormant line. In the QTL-containing region there is no predicted gene that has been assigned to ABA biosynthetic or metabolic pathways. Thus, it is concluded that the qSD12 underlying gene promotes ABA accumulation in early developing seeds to induce primary seed dormancy.