The genetics of barley low-tillering mutants: low number of tillers-1 (lnt1)
The genetics of barley low-tillering mutants: low number of tillers-1 (lnt1)
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DOI：
10.1007/s00122-010-1342-5
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发表时间：
2010-08-01
影响因子：
5.4
通讯作者：
Muehlbauer, Gary J.
中科院分区：
文献类型：
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作者：
Dabbert, Timothy;Okagaki, Ron J.;Muehlbauer, Gary J.
大麦（Hordeum vulgare L.）在低分蘖数1（Lnt 1）基因上携带隐性突变的水稻不发育二次分蘖，到成熟时仅发育1 - 4个分蘖。双突变体分析表明，lnt 1突变体对6个低分蘖和高分蘖突变体中的5个具有上位性。双突变体的lnt 1和低分蘖突变体intermedium-b（int-b）导致在一个单茎植物，表明协同相互作用，Lnt和Int-b功能在单独的分蘖途径。RNA分析确定了70个转录本，与野生型相比，在lnt 1突变体中丰度增加或减少。在lnt 1突变体中转录水平降低的一个基因是Bell样同源结构域转录因子JuBel 2。lnt1.a突变体中的JuBel 2等位基因含有移码突变，该突变消除了大部分预测的多肽，表明Lnt 1基因编码JuBel 2。以往对低分蘖突变体无下胚轴（als）的研究表明，als和lnt 1与其它分蘖突变体的分蘖表型和遗传互作非常相似。然而，转录组是非常不同的，许多转录本注释为压力和防御反应表现出增加丰度的ALS突变体。这种差异表明，在分蘖的遗传控制中，Als和Lnt 1之间存在功能分离。
Barley (Hordeum vulgare L.) carrying recessive mutations at the Low number of tillers1 (Lnt1) gene does not develop secondary tillers and only develops one to four tillers by maturity. Double mutant analysis determined that the lnt1 mutant was epistatic to five of the six low and high tillering mutants tested. Double mutants of lnt1 and the low tillering mutant intermedium-b (int-b) resulted in a uniculm plant, indicating a synergistic interaction and that Lnt and Int-b function in separate tillering pathways. RNA profiling identified 70 transcripts with either increased or decreased abundance in the lnt1 mutant compared to wild-type. One gene with reduced transcript levels in the lnt1 mutant was the BELL-like homeodomain transcription factor JuBel2. The JuBel2 allele in the lnt1.a mutant contained a frameshift mutation that eliminated most of the predicted polypeptide, indicating that the Lnt1 gene encodes JuBel2. Previous studies with the low-tillering mutant absent lower laterals (als) showed that the tillering phenotypes and genetic interactions of als and lnt1 with other tillering mutants were very similar. However, the transcriptomes were very different; many transcripts annotated as stress and defense response exhibited increased abundance in the als mutant. This difference suggests a functional separation between Als and Lnt1 in the genetic control of tillering.