Switchgrass SBP-box transcription factors PvSPL1 and 2 function redundantly to initiate side tillers and affect biomass yield of energy crop.
Switchgrass SBP-box transcription factors PvSPL1 and 2 function redundantly to initiate side tillers and affect biomass yield of energy crop.
复制标题
柳枝稷SBP-box转录因子PvSPL1和2冗余地发挥作用以启动侧耕并影响能源作物的生物量产量
DOI：
10.1186/s13068-016-0516-z
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发表时间：
2016
影响因子：
6.3
通讯作者：
Fu C
中科院分区：
文献类型：
--
作者：
Wu Z;Cao Y;Yang R;Qi T;Hang Y;Lin H;Zhou G;Wang ZY;Fu C
背景：柳枝稷是用于生物能源生产的专用木质纤维素原料。SQUAMOSA启动子结合蛋白（SBP-盒）样转录因子（SPLs）显著改变植物结构和植物向生殖阶段的转变，因此，它们是柳枝稷生物量产量遗传改良的有希望的候选者。然而，SPL基因的全基因组识别和功能特性还有待调查在草本能源crops.Results：我们确定了35个全长SPL基因在柳枝稷基因组。PvSPLs的系统发育关系和表达模式为PvSPLs的功能鉴定提供了基础信息。基于PvSPLs的全球概述，我们探索了miR 156靶向的PvSPL 1和PvSPL 2的生物学功能，它们是柳枝稷中SPL家族的密切相关成员。结果表明，PvSPL 1和PvSPL 2对侧分蘖的发生具有冗余调节作用，但对分蘖的发生和节间的发生没有影响。一致地，在miR 156过表达的转基因植物中miR 156抗性rPvSPL 2的过表达极大地降低了分蘖起始，但没有挽救延迟的开花和增加的节间数。此外，抑制柳枝稷中的PvSPL 2活性增加了生物量产量，降低了木质素积累，从而提高了可溶性糖的总量。结论：我们的研究结果表明，不同的miR 156靶向PvSPL亚家族基因的功能主要在柳枝稷中的某些生物过程。因此，PvSPL 2及其同源基因可作为能源作物分子育种的重要靶点，用于开发高产生物燃料的新种质。
Background:Switchgrass (Panicum virgatum L.) is a dedicated lignocellulosic feedstock for bioenergy production. The SQUAMOSA PROMOTER-BINDING PROTEIN (SBP-box)-LIKE transcription factors (SPLs) change plant architecture and vegetative-to-reproductive phase transition significantly, and as such, they are promising candidates for genetic improvement of switchgrass biomass yield. However, the genome-wide identification and functional characterization of SPL genes have yet to be investigated in herbaceous energy crops.Results:We identified 35 full-length SPL genes in the switchgrass genome. The phylogenetic relationship and expression pattern of PvSPLs provided baseline information for their function characterization. Based on the global overview of PvSPLs, we explored the biological function of miR156-targeted PvSPL1 and PvSPL2, which are closely related members of SPL family in switchgrass. Our results showed that PvSPL1 and PvSPL2 acted redundantly to modulate side tiller initiation, whereas they did not affect phase transition and internode initiation. Consistently, overexpression of the miR156-resistant rPvSPL2 in the miR156-overexpressing transgenic plants greatly reduced tiller initiation, but did not rescue the delayed flowering and increased internode numbers. Furthermore, suppression of PvSPL2 activity in switchgrass increased biomass yield and reduced lignin accumulation, which thereby elevated the total amount of solubilized sugars.Conclusions:Our results indicate that different miR156-targeted PvSPL subfamily genes function predominantly in certain biological processes in switchgrass. We suggest that PvSPL2 and its paralogs can be utilized as the valuable targets in molecular breeding of energy crops for developing novel germplasms with high biofuel production.