Biology subjects

Wu, C. A.

Publications and source records attributed to Wu, C. A..

3 recordsLinked to original sources

bioRxiv2021

SiCEP3, a C-terminally encoded peptides from Setaria italica, promotes ABA import and signaling pathway

C-terminally encoded peptides (CEPs) are small peptides, typically post-translationally modified, and highly conserved in many species. CEPs are known to play roles in inhibition of plant growth and regulation of development, but the mechanisms are not well understood. In this study, we searched for CEP peptides in foxtail millet (Setaria italica). The 14 peptides we identified are divided into two subfamilies. The transcripts of most SiCEPs were more abundant in roots than in other tissues. SiCEP3, SiCEP4, and SiCEP5 were also expressed at high levels in panicles. Moreover, expression of all SiCEPs was induced by biotic stress and phytohormones. SiCEP3 overexpression and application of biosynthetic SiCEP3 both inhibited the growth of seedlings. In the presence of ABA, growth inhibition and ABA content of seedlings increased with the concentration of SiCEP3. Transcripts encoding two ABA transporters and one ABA receptor were induced by SiCEP3, ABA, and the two in combination. Further analysis revealed that SiCEP3 promoted ABA transport via NRT1.2 and ABCG40. In addition, SiCEP3, ABA, or the combination inhibited the kinase activities of CEP receptors CEPR1/2. Taken together, our results indicated that the CEP-CEPR module mediates ABA signaling by regulating ABCG40, NRT1.2, and PYL4 in planta. HighlightSiCEP3, a C-terminally encoded peptide, can promote ABA import and signaling pathway by inhibiting the kinase activity of its receptors under abiotic stress in Setaria italica.

cell biology↗

bioRxiv2020

Evolution of multiple postzygotic barriers between species in the Mimulus tilingii species complex

Species are often defined by their ability to interbreed (i.e., Biological Species Concept), but determining how and why reproductive isolation arises between new species can be challenging. In the Mimulus tilingii species complex, three species (M. caespitosa, M. minor, and M. tilingii) are largely allopatric and grow exclusively at high elevations (>2000m). The extent to which geographic separation has shaped patterns of divergence among the species is not well understood. In this study, we determined that the three species are morphologically and genetically distinct, yet recently diverged (<400kya). Additionally, we performed reciprocal crosses within and between the species and identified several strong postzygotic reproductive barriers, including hybrid seed inviability, F1 hybrid necrosis, and F1 hybrid male and female sterility. In this study, such postzygotic barriers are so strong that a cross between any species pair in the M. tilingii complex would cause nearly complete reproductive isolation. We consider how geographical and topographical patterns may have facilitated the evolution of several postzygotic barriers and contributed to speciation of closely related members within the M. tilingii species complex.

evolutionary biology↗

bioRxiv2019

Convergence of glandular trichome morphology and chemistry in two montane monkeyflower species

Two distantly-related North American montane monkeyflower species, Mimulus lewisii and Mimulus tilingii, possess glandular trichomes. In this study, we characterized the morphological and histochemical features of these glandular trichomes. For each species, we used traditional light microscopy and scanning electron microscopy (SEM) to examine morphological characteristics, and determined the main components of the secretory products using histochemical and thin layer chromatography (TLC) staining techniques. We identified type VI glandular trichomes on leaf surfaces in both species of monkeyflowers. These trichomes exhibited stalk-cell lengths and head-cell counts that varied across adaxial and abaxial leaf surfaces, stems, and sepals. Both species contained secretory products within the cuticle of the trichome head, which releases the subcuticular metabolites when ruptured. Histochemical tests in both M. lewisii and M. tilingii confirmed that secretions contained lipids and polysaccharides. TLC plate staining indicated the presence of UV active compounds with polyalcohols, lipids, and amines. The common morphology and chemistry of the glandular trichomes suggests an analogous response to similar environmental conditions in these evolutionary distant montane monkeyflowers.

plant biology↗