Progressive Regulation of Sesquiterpene Biosynthesis in Arabidopsis and Patchouli (Pogostemon cablin) by the miR156-Targeted SPL Transcription Factors

Abstract

Plant metabolites vary at different stages of life cycle. Although it is well documented that environmental factors stimulate biosynthesis of secondary metabolites, the regulation by endogenous developmental cues remains poorly understood. The microRNA156 (miR156)-tageted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) factors function as a major age cue in regulating developmental phase transition and flowering. We show here that the miR156-targeted SPL transcription factor plays an important role in the spatiotemporal regulation of sesquiterpene biosynthesis. In Arabidopsis thaliana, the miR156-SPL module regulates the formation of (E)-β-caryophyllene in flowering stage through modulating expression of the sesquiterpene synthase gene TPS21. We demonstrated that SPL9 directly binds to TPS21 promoter and activates its expression. In the perennial fragrant herb Pogostemon cablin, the accumulation of "patchouli oil", largely composed of sesquiterpenes dominated by (-)-patchoulol, is also age-regulated, and the SPL promotes biosynthesis of sesquiterpenes in elder plants by up-regulating patchoulol synthase (PatPTS) gene expression. As miR156-SPLs are highly conserved in plants, our finding not only uncovers a molecular link between developmental timing and sesquiterpene production, but also suggests a new strategy to engineer plant for accelerated growth with enhanced production of terpenoids.

The interactions of PhSPL17 and PhJAZ1 mediate the on‐ and off‐year moso bamboo (Phyllostachys heterocycla) resistance to the Pantana phyllostachysae larval feeding

“…S2), implying that the foundation of the on-and off-year leaf process is linked to leaf ageing. 31 This result supports our earlier data showing that the expression level of the age-process marker gene PhSPL17 alternated with on-and off-years in moso bamboo (Fig. S4).…”

The role of volatiles in plant communication

“…microRNAs (miRNAs), although quantitatively by far a minor type amongst the total of small RNAs encountered, have been studied most extensively. In relation to specialized metabolites, there appears to be a pivotal role for miRNA156b (Schwab et al ., ; Gou et al ., ; Yu et al ., ). Yu et al .…”

Plant developmental transitions: the role of microRNAs and sugars

“…For example, SPL9, as a canonical transcription activator, induces flowering through activating MADS-box genes APETALA1 (AP1), FRUITFULL (FUL) and SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1) [25,35], or promotes terpene biosynthesis through the activation of terpene synthase TPS21 [40 ]. By contrast, SPL9 represses cytokinin response and anthocyanin production through binding with the B-type ARABIDOPSIS RESPONSE REGULATORs (ARRs), the master regulators in the cytokinin signaling pathway, or PAP1, the MYB transcription factor in the anthocyanin biosynthetic pathway [36,38].…”