【作者】 仝征； 董婷婷； 李邱华； 王瑞； 洪波； 何俊娜；

【Author】 Zheng Tong;Tingting Dong;Qiuhua Li;Rui Wang;Bo Hong;Junna He;Beijing Key Laboratory of Flower Development and Quality Control, College of Horticulture, China Agricultural University;

【机构】 花卉发育与品质调控北京市重点实验室中国农业大学园艺学院；

【摘要】 百合在世界各地广泛种植、深受人们喜爱,但它们的大花药开裂时会散落大量的花粉,污染花瓣和衣物,我们希望研究花药发育和开裂的分子机制解决该问题。在实验室前期的花药发育转录组数据中,我们发现两个LoMYB21的同源基因,将这两个基因分别命名为LoMYB21-1和LoMYB21-2。通过与其他物种的氨基酸序列进行比对,发现该基因属于R2R3类MYB转录因子。进化树分析表明,该基因与拟南芥At MYB21和At MYB24基因同源性高,推测在功能上可能是一致的,即参与JA调控的雄性不育。所以,我们从东方百合‘西伯利亚’中克隆了LoMYB21-1并提交至Genbank,登录号为KT759161。实时定量结果表明,LoMYB21主要在花药、花丝和柱头中表达,且在百合花药发育后期高表达,在花药中的表达受到JA的抑制,在百合叶片中的表达受到JA的诱导。酵母单杂交实验显示,LoMYB21具有转录激活活性;截掉C端的自激活域后,LoMYB21失去转录活性,证明转录激活域位于C端。本氏烟草中的瞬时表达实验证明LoMYB21定位于细胞核。病毒诱导的基因沉默(VIGS)实验导致百合花药中LoMYB21表达量降低,沉默植株出现了花药延迟开裂表型,且JA生物合成和信号传导相关的基因的表达降低。使用DEX处理的DEX::LoMYB21转基因拟南芥花序发育不良,长角果少,茎平卧,与之对应的是超表达植株中JA生物合成和信号基因的更高表达。这些结果表明,LoMYB21可能在花药发育后期通过影响JA生物合成和信号传导调节百合花药开裂,这为花药不开裂百合的培育提供候选基因和理论支持。综上所述,百合LoMYB21在花药发育后期表达,定位于细胞核中,具有转录激活活性,可能通过影响JA的生物合成和信号转导调控花药的开裂过程。更多还原

【Abstract】 Lilies are widely grown and loved all over the world, but their large anthers will scatter a lot of pollen when they open, which will contaminate petals and clothing. We want to study the molecular mechanism of anther development and dehiscence to solve this problem. In our previous anther development transcriptome data,we have found two homologous genes of LoMYB21, which were named LoMYB21-1 and LoMYB21-2 respectively.By aligning with the amino acid sequences of other species, LoMYB21 belongs to the R2R3 class of MYB transcription factors. The phylogenetic tree analysis showed that this gene has high homology with At MYB21 and At MYB24.Their function may be consistent that they were involved in male sterility regulated by JA. Therefore, we cloned LoMYB21-1 from Oriental Lily ’Siberia’ and submitted it to Genbank with accession number KT759161.The real-time quantitative results showed that LoMYB21 expressed mainly in lily anthers, filaments and stigmas, and expressed highly in the later development stage of lily anthers. The expression in anthers was inhibited by JA, and the expression in lily leaves was induced by JA. Yeast one-hybrid experiments showed that LoMYB21had transcriptional activation activity; after truncation of the C-terminal self-activation domain, LoMYB21 lost its transcriptional activity, proving that the transcriptional activation domain was located at the C-terminal. Transient expression experiments in N. benthamiana demonstrated that LoMYB21 localized in the nucleus. Virus-induced gene silencing(VIGS) experiments resulted in decreased expression of LoMYB21 in lily anthers, delayed anther dehiscence phenotype in silenced plants, and decreased expression of genes related to JA biosynthesis and signaling.The DEX::LoMYB21 transgenic Arabidopsis treated with DEX had stunted inflorescences, few siliques, and recumbent stems, which corresponded to higher expression of JA biosynthesis and signaling genes in overexpressing plants. These results suggest that LoMYB21 may regulate lily anther dehiscence by affecting JA biosynthesis and signaling at the later development stage of anthers, which provides candidate genes and theoretical support for the cultivation of anther non-dehiscent lily.In conclusion, LoMYB21 expresses at the later development stage of lily anthers, localize in the nucleus, and has transcriptional activation activity, which may regulate the dehiscence process of anthers by affecting the biosynthesis and signal transduction of JA.更多还原