Switchgrass SBP-box transcription factors PvSPL1 and 2 function redundantly to initiate side tillers and affect biomass yield of energy crop. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Wu, Zhenying; Cao, Yingping; Yang, Ruijuan; Qi, Tianxiong; Hang, Yuqing; Lin, Hao; Zhou, Gongke; Wang, Zeng-Yu; Fu, Chunxiang
• Is Part Of: Biotechnology for biofuels. Volume 9:Issue 1(2016)
• Page Start: 1
• Page End: 15
• Publication Date: 2016-12
• Subjects: Energy crop -- Biomass -- Lignin -- SPL transcription factor -- Transgenic switchgrass -- Tiller initiation; Biotechnology -- Periodicals; Biomass energy -- Periodicals; Energy-Generating Resources -- Periodicals; 662.88
• DOI: 10.1186/s13068-016-0516-z
• Languages: English
• ISSNs: 1754-6834

Abstract

Abstract 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 ofSPL genes have yet to be investigated in herbaceous energy crops. Results We identified 35 full-lengthSPL genes in the switchgrass genome. The phylogenetic relationship and expression pattern ofPvSPLs provided baseline information for their function characterization. Based on the global overview ofPvSPLs, we explored the biological function of miR156-targetedPvSPL1 andPvSPL 2, which are closely related members ofSPL family in switchgrass. Our results showed thatPvSPL1 andPvSPL 2 acted redundantly to modulate side tiller initiation, whereas they did not affect phase transition and internode initiation. Consistently, overexpression of the miR156-resistantrPvSPL2 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-targetedPvSPL subfamily genes function predominantly in certain biological processes in switchgrass. We suggest thatPvSPL2 and its paralogs can be utilized as the valuable targets in molecular breeding of energy crops for developing novel germplasms with high biofuel production.