Biology subjects

Liu, S.-S.

Publications and source records attributed to Liu, S.-S..

4 recordsLinked to original sources

bioRxiv2024

Auxin-salicylic acid seesaw regulates the age-dependent balance between plant growth and herbivore defense

Plants must fine-tune their needs for growth and defense. According to the Plant Vigor Hypothesis, younger, more vigorous plants tend to be more susceptible to herbivores compared to older, mature plants, yet the molecular mechanisms underlying this dynamic remain elusive. Here, we uncover a hormonal crosstalk framework that orchestrates the age-related balance between plant growth and herbivore defense. We demonstrate that the accumulation of salicylic acid (SA), synthesized by Nicotiana benthamiana phenylalanine ammonia-lyase 6 (NbPAL6), dictates insect resistance in adult plants. The expression of NbPAL6 is driven by the key transcription factor, NbMYB42, which is regulated by two interacting auxin response factors, NbARF18La/b. In juvenile plants, higher auxin levels activate NbmiR160c, a microRNA that simultaneously silences NbARF18La/b, subsequently reducing NbMYB42 expression, lowering SA accumulation, and thus weakening herbivore defense. Furthermore, excessive SA accumulation in juvenile plants enhances defense but antagonizes auxin signaling, impairing early growth. Our findings suggest a seesaw-like model that balances growth and herbivore defense depending on the plants developmental stage.

plant biology↗

bioRxiv2023

A New Feature of the Laboratory Model Plant Nicotiana benthamiana: Dead-End Trap for Sustainable Field Pest Control

O_LIHemiptera and Thysanoptera insects pose persistent threats to agricultural production. Conventional management strategies involve the release of chemical or plastic agents, causing adverse environmental and global health issues. Notably, Nicotiana benthamiana, a globally utilized model plant, exhibits remarkable lethal effects and attraction towards these pests. C_LIO_LIIn this study, we explored the potential of using N. benthamiana for Hemiptera and Thysanoptera pest control in the laboratory and field. Through net cover and three field assays over two years, we demonstrated the efficacy and benefits of using N. benthamiana as a field-deployed pest control dead-end trap. C_LIO_LIN. benthamiana demonstrated nearly 100% lethality to whiteflies, aphids, and thrips, with emitted volatiles attracting these insects. Field trials showed that potted and planted N. benthamiana blocks and traps whiteflies and thrips from several Solanaceae and Cucurbitaceae crops effectively, comparable to common commercial yellow and blue sticky boards. Moreover, N. benthamiana in the field exhibits robust growth in commercial greenhouses without negatively impacting crop growth, natural enemies, and pollinators. C_LIO_LIOur study introduces an innovative, easily implementable, and sustainable approach for controlling Hemiptera and Thysanoptera pests. Moreover, it unveils the novel utility of N. benthamiana in field-based pest management. C_LI

plant biology↗

bioRxiv2021

Presynaptic HCN channels constrain GABAergic synaptic transmission in pyramidal cells of the medial prefrontal cortex

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are widely expressed in neurons in the central nervous system. It has been documented that HCN channels regulate the intrinsic excitability of pyramidal cells in the medial prefrontal cortex (mPFC) of rats. Here, we report that HCN channels limited GABAergic transmission onto pyramidal cells in the mPFC. Pharmacological block of HCN channels resulted in a significant increase in the frequency of both spontaneous and miniature inhibitory postsynaptic currents (IPSCs) in mPFC pyramidal cells. Such facilitation effect on mIPSCs required presynaptic Ca2+ influx and reversed by high-dose cAMP. Such facilitation did not exist in the presence of the T-type Ca2+ channel selective blockers. Immunofluorescence staining revealed that HCN channels expressed in presynaptic GABAergic terminals, as well as in both soma and neurite of parvalbumin-expressing (PV-expressing) basket cells in the mPFC. The present results indicate that HCN channels in GABAergic interneurons, most likely PV-expressing basket cells, constrain inhibitory control over layer 5-6 pyramidal cells through restricting presynaptic Ca2+ entry.

neuroscience↗

bioRxiv2020

Gut expressed vitellogenin is hijacked by a virus to facilitate its spread

Insect vitellogenin (Vg) has been considered to be synthesized in the female fat body, secreted into hemolymph, and taken up by developing oocytes to serve as nutrition for embryo development. However, the expression and function of Vg in other tissues are largely unknown. Here, we show that Vg is expressed in the whitefly midgut epithelial cells and secreted into gut lumen where it binds to the microvillar membrane. Furthermore, we find that the midgut expressed Vg is hijacked by Tomato yellow leaf curl virus to facilitate the movement of virus crossing the midgut wall. Silencing of Vg or immune-blocking the interaction between viral coat protein and midgut Vg inhibited virus movement across the midgut wall and decreased virus transmission. Our findings show possession of functional Vg in the midgut of an insect, and reveal a novel mechanism involved in the movement of virus crossing the midgut barrier of vector insect.

microbiology↗