Biology subjects

Pozueta-Romero, J.

Publications and source records attributed to Pozueta-Romero, J..

3 recordsLinked to original sources

bioRxiv2026

Acetic acid enhances tolerance to long-term water deficit in tomato by partially buffering transcriptomic and proteomic reprogramming independently of canonical jasmonate signalling

Acetic acid (AA), a volatile compound present in diverse microbial-derived biostimulants, enhances drought tolerance in plants. In Arabidopsis, soil-applied AA action has been linked to histone H4 acetylation and activation of jasmonate (JA) signalling. However, the mechanisms underlying AA action in crops of agronomic interest remain poorly understood. Here, we used an integrative approach to evaluate the effects of soil-applied AA on fruit yield, physiological performance, and leaf transcriptomic and proteomic profiles of tomato plants grown under optimal and suboptimal irrigation conditions (OIC and SOIC, respectively). While AA had little effect under OIC, it significantly enhanced fruit yield and photosynthesis under SOIC. Long-term water deficit triggered extensive transcriptomic and proteomic reprogramming, particularly affecting photosynthesis, RNA processing, protein biosynthesis-, modification- and homeostasis-related processes. Under SOIC, AA induced marked molecular changes that were not consistent with activation of canonical JA signaling pathways. Notably, only [~] 10% of the drought- or AA-responsive proteins were associated with corresponding transcript changes, highlighting a predominant role of regulatory layers beyond the transcriptional control to both long-term water deficit- and AA-induced protein remodeling. Strikingly, AA attenuated 47% and 35% of the transcriptomic and proteomic alterations induced by long-term water deficit, respectively. In addition, AA altered the abundance of numerous proteins that do not respond to drought, particularly ribosomal proteins and proteins involved in RNA processing. Collectively, our findings indicate that AA enhances tolerance to prolonged water deficit in tomato through mechanisms largely independent of canonical JA signaling and involving extensive downstream regulatory processes that partially mitigate stress-induced molecular reprogramming.

Plant Biology↗

bioRxiv2025

CLPC2 plays specific roles in CLP complex-mediated regulation of growth, photosynthesis, embryogenesis and response to growth-promoting microbial compounds

In Arabidopsis, exposure to growth-promoting microbial volatile compounds (VCs) enhances CLPC2 levels. This chaperone forms part of the CLP protease complex, which ensures the correct functioning of essential processes in plastids. Previous studies indicated considerable functional redundancy of CLPC2 with its dominant paralogue CLPC1. However, the function and action mechanism of CLPC2 still remain unknown. Here we found that CLPC2-lacking clpc2-2 mutants were unresponsive to microbial VCs, whereas clpc1-1 knockout mutants exhibited a WT-like response to VCs when grown on sucrose-containing medium. Unlike clpc1-1, clpc2-2 plants presented a fully functional photosystem II and lower than WT stomatal conductance. Furthermore, clpc2-2 plants, but not clpc1-1 plants, produced wrinkled seeds with delayed embryonic development and reduced postgerminative establishment rates that resembled those of mutants lacking P and R components of the CLP proteolytic core. Proteomic analyses revealed that knocking out of CLPC2 enhanced the levels of chloroplastic proteins that are essential for growth, embryo development and seedling establishment. These changes differed from those promoted by the lack of CLPC1, but partially resembled those promoted by CLPPR core inactivation. Nearly 40% of the proteins differentially accumulated by the lack of CLPC2 were VC-responsive. Notably, 35S promoter-driven CLPC2 expression promoted changes in the proteome similar to those promoted by the lack of CLPC1. Collectively, our findings highlighted contrasting functional and molecular specificities for CLPC1 and CLPC2, and provided strong evidence that CLPC2 plays specific roles in CLP complex-mediated regulation of plant growth, photosynthesis, embryogenesis, postgerminative seedling establishment and microbial VC responsiveness.

plant biology↗

bioRxiv2023

RAPID ALKALINIZATION FACTOR 22 is a key modulator of the proliferation and hyper-elongation responses of root hairs to microbial volatiles in Arabidopsis

RAPID ALKALINIZATION FACTOR (RALF) peptides are important players in regulating cell expansion. In Arabidopsis, volatile compounds (VCs) emitted by the fungal phytopathogen Penicillium aurantiogriseum promote root hair (RH) proliferation and hyper-elongation through ethylene and enhanced photosynthesis signalling actions. A striking alteration in the proteome of fungal VC-treated roots involves up-regulation of RALF22. To test the possible involvement of RALF22 in the fungal VC-promoted RH changes, we characterized RH density and number responses to fungal VCs in ralf22 and fer-4 plants impaired in RALF22 and its receptor FERONIA, respectively. Unlike WT plants, ralf22 and fer-4 RHs responded weakly to fungal VCs, strongly indicating that the RALF22-FERONIA module is a key determinant of the RH response to fungal VCs. To investigate the regulatory mechanisms behind this response, we analysed the RALF22 transcript levels in roots of etr1-3 and eir1 ethylene signalling mutants and those of ethylene-responsive, RH-related RSL4, RHD2, PRX1 and PRX44 transcripts in ralf22 and fer-4 roots. Moreover, we characterized the RH and RALF22 transcript level responses to fungal VCs of the cfbp1 mutant defective in photosynthetic responsiveness to VCs. Unlike in WT roots, fungal VCs weakly enhanced RALF22 expression in etr1-3, eir1 and cfbp1 roots, and RSL4, RHD2, PRX1 and PRX44 expression in ralf22 and fer-4 roots. In addition, fungal VCs weakly promoted RH changes in cfbp1 roots. Collectively, our findings showed that the ethylene and enhanced photosynthesis signalling-mediated RH response to fungal VCs involves RALF22-FERONIA.

plant biology↗