Biology subjects

Opachaloemphan, C.

Publications and source records attributed to Opachaloemphan, C..

4 recordsLinked to original sources

bioRxiv2026

The FERONIA receptor kinase is required for high humidity responses in Arabidopsis

High humidity greatly influences plant growth and development and triggers adaptive physiological responses such as leaf hyponasty (elongation of leaf petiole and upward leaf movement). A recent study identified Cyclic Nucleotide-Gated Ion Channels 2 and 4 (CNGC2/4)-mediated Ca2+ influx and Calmodulin Binding Transcription Activators 2 and 3 (CAMTA2/3)-mediated transcription as essential for high humidity response in Arabidopsis, but the upstream regulators that control these pathways remain unknown. Here, we show that the receptor-like kinase FERONIA and its co-receptor LORELEI-LIKE GPI-ANCHORED PROTEIN1 (LLG1) are required for a large portion of high humidity-associated Arabidopsis transcriptomic changes, including CNGC2, CAMTA-regulated genes, and cell wall remodeling genes, and for high humidity-induced leaf hyponasty. High humidity triggers a previously uncharacterized petiole-localized Ca2+ waves that precede hyponastic leaf movement. The petiole-localized Ca2+ signals were significantly altered in the fer-4 mutant. Thus, FERONIA is a key regulator of plant responses to extracellular high humidity. Highlights FERONIA plays a prominent role in transcriptomic responses to high humidity FERONIA is required for high humidity-induced leaf hyponasty High humidity induces petiole calcium waves FERONIA is required for normal petiole calcium waves in response to high humidity

plant biology↗

bioRxiv2025

Augment rice ANNEXIN expression to counter planthopper NlAnnexin-like5 as an anti-virulence strategy against a major crop pest

The brown planthopper (BPH) is the most devastating insect pest in rice, posing a serious threat to global rice production. One attractive control strategy would be based on the understanding of the virulence mechanisms of BPH at the molecular level and then designing targeted methods to neutralize such mechanisms. Salivary proteins of BPH are important players in mediating rice-BPH interactions. Here, we describe a pivotal role of a watery saliva protein, NlAnnexin-like5 (NlANX5), in the rice-BPH interaction. RNA interference (RNAi) of NlANX5 greatly compromised BPH feeding performance and survival rate on rice plants. NlANX5-RNAi BPH triggered a rapid calcium ion influx in rice cells. The feeding and survival defects of NlANX5-RNAi BPH can be restored in NlANX5-expressing transgenic rice plants. NlANX5 targets rice annexin (OsANN) proteins, including OsANN2 and OsANN8. Further analysis with NlANX5 and OsANN2 as well as OsANN8 showed that NlANX5 displaces OsANN2 and OsANN8 from the rice cell membrane. The osann2 osann8 mutant rice plants are hypersusceptible to BPH infestation. In contrast, enhanced expression of OsANN2 and OsANN8 gene resulted in robust rice resistance against BPH. This study highlights a successful example of identifying and augmenting the expression of the host targets of a major BPH virulence effector as a promising anti-virulence strategy against an important crop pest. Significance StatementInsect pests pose a serious biotic threat to crop production worldwide. Understanding how insect pests attack plants could inspire innovative pest control measures to enhance global food security. The brown planthopper (BPH; Nilaparvata lugens St[a]l) is the most devastative insect pest in rice. In this study, we discovered that BPH secretes a salivary protein, NlAnnexin-like5 (NlANX5), to target rice host annexins that are associated with calcium fluxes and activation of multiple rice defense pathways. This knowledge led to employing enhanced expression of rice annexin-encoding genes to successfully defeat the virulence function of NlANX5. Results have significant implications in the development of anti-virulence breeding strategies against BPH.

plant biology↗

bioRxiv2022

Insulin signaling and extended longevity in ants

In most organisms, the cost of reproduction is a shorter lifespan. However, the reproductive caste in eusocial insect species (queen) exhibits an extraordinarily longer lifespan than non-reproductive castes (workers) despite having a similar genome, thus contradicting the aging dogma. In the absence of the queen, Harpegnathos saltator ants can undergo a caste switch from workers to reproductive pseudo-queens (gamergates). Gamergates exhibit a dramatically prolonged lifespan. When placed in the presence of a reproductive, they revert to worker status and their lifespan is then shortened accordingly. To understand this unique relationship between reproduction and longevity, we analyzed tissue-specific gene expression between castes. Insulin is upregulated in the gamergate brain that leads to oogenesis, but surprisingly correlates with extended longevity. This correlates with increased lipid synthesis and elevated production of vitellogenin in the fat body, which are both transported to the egg. We show that the production of vitellogenin in the fat body is due to the systemic activation of the MAPK branch of the insulin/IGF signaling (IIS)-pathway. In contrast, reduced expression of insulin receptors in the fat body of gamergates and the production in their developing ovary of an anti-insulin (Imp-L2) lead to the downregulation of the AKT/FOXO branch of the IIS-signaling pathway in the fat body, and to the dramatically extended longevity. This reveals a dual-pathway mechanism that reconciles increased longevity in the context of active reproduction in eusocial insects. One Sentence SummaryInsulin-dependent reproduction in ants correlates with extended longevity through insulin inhibition by anti-insulin Imp-L2.

physiology↗

bioRxiv2017

Olfactory Receptors Are Required For Social Behavior And Neural Plasticity In Ants, As Evidenced By CRISPR-Mediated Gene Knockout

The chemosensory system is key to establishing and maintaining social structure in eusocial insects. Ants exhibit cooperative colonial behaviors reflective of an advanced form of sociality with an extensive dependency on communication. Cuticular hydrocarbons (CHCs) serve as pheromones and cues that regulate multiple aspects of social interactions and behaviors in ants. The perception of CHCs entails odorant receptor neurons (ORNs) that express specific odorant receptors (ORs) encoded by a dramatically expanded Or gene family in ants. Until recently, studies of the biological functions of ORs in eusocial insects were stymied by the lack of genetic tools. In most eusocial insect species, only one or a few queens in a colony can transmit the genetic information to their progeny. In contrast, any worker in the ant Harpegnathos saltator can be converted into a gamergate (pseudo-queen), and used as a foundress to engender an entire new colony and be crossed for genetic experiments. This feature facilitated CRISPR-Cas9 gene targeting to generate a germline mutation in the orco gene that encodes the obligate co-receptor whose mutation should significantly impact ant olfaction. Our results show that Orco exhibits a conserved role in the perception of general odorants but also a role in reproductive physiology and social behavior plasticity in ants. Surprisingly, and in contrast to other insect systems, the loss of OR functionality also dramatically reduces the development of the ant antennal lobe where ORNs project. Taken together, these findings open the possibility of studying the genetics of eusociality and provide inroads towards understanding the function of the expanded ORs family in eusocial insects in regulating caste determination, social communication and neuronal plasticity.

neuroscience↗