Biology subjects

Gomez-Cadenas, A.

Publications and source records attributed to Gomez-Cadenas, A..

6 recordsLinked to original sources

bioRxiv2025

Enhanced cell aggregation in the Chlamydomonas reinhardtii rbo1 mutant in response to multifactorial stress combination

Global change factors associated with climate change and increased pollution are subjecting plants, microbes, and different ecosystems to conditions of multifactorial stress combination (MFSC). While recent studies centered on the effects of MFSC on different plants and ecosystems, much less is known about how these conditions impact unicellular organisms. Here, we report on the physiological and proteomic responses of wild type and respiratory burst oxidase homolog 1 (rbo1) mutant cells of Chlamydomonas reinhardtii to a MFSC of 5 different abiotic stresses. While several similarities were found between plant and C. reinhardtii responses to MFSC, our work revealed that MFSC induces aggregation in the unicellular organism C. reinhardtii. We further show that MFSC induced aggregation is enhanced in the rbo1 mutant and can be triggered by H2O2. As aggregation typically leads to reduced growth, respiration and/or photosynthesis, enhanced aggregation of unicellular organisms in different ecosystems subjected to MFSC could explain part of the negative impacts of MFSC on the services they provide. Our findings shed new light on the response of unicellular organisms to MFSC and suggest that one of the main drivers leading to multicellularity during evolution was early conditions of MFSC under an oxygenated environment.

plant biology↗

bioRxiv2024

Growth arrest is a DNA damage protection strategy in plants

When exposed to stress, plants slow down their growth while activating defensive mechanisms. This behaviour has been proposed to help plants reallocate resources and meet the energy demands required for survival. In this study, we show instead that plants can grow under limited water availability without compromising their tolerance to the stress. However, cells that continue to divide under stress accumulate DNA damage, which frequently leads to cell death. Given that the DNA lesions are observed in the apical stem cells that give rise to all plant organs, including flowers, we propose that systemic growth arrest is used as a defense strategy that plants employ not only to maximize individual fitness, but also to ensure the accurate transmission of genetic information to their progeny.

plant biology↗

bioRxiv2023

Within-host virus spreading and tolerance to infection are key factors of the Arabidopsis thaliana age-dependent susceptibility to viral infections

Arabidopsis thaliana is more susceptible to certain viruses during its later developmental stages. The reasons for this age-dependent susceptibility are not fully understood. Here we explored the possible causes by studying the A. thaliana infection response to turnip mosaic virus at three developmental stages: vegetative, bolting and flowering. We found that infected plants at later stages downregulate cell wall fortification genes and that this downregulation facilitates the viral spread and systemic infection. Despite being more susceptible to infection, infected flowering plants are more fertile (i.e., produce more viable seeds) than vegetative and bolting infected plants; that is, they have greater fitness than plants infected at these earlier developmental stages. Treatment of postbolting plants with salicylic acid increases resistance to infections at the cost of significantly reducing fertility. Together, these observations suggest a negative trade-off between viral susceptibility and plant fertility. Our findings point towards a development-dependent tolerance to infection.

microbiology↗

bioRxiv2021

GABA plays a key role in plant acclimation to a combination of high light and heat stress

Plants are frequently subjected to different combinations of abiotic stresses, such as high light intensity and elevated temperatures. These environmental conditions pose an important threat to agriculture production, affecting photosynthesis and decreasing yield. Metabolic responses of plants, such as alterations in carbohydrates and amino acid fluxes, play a key role in the successful acclimation of plants to different abiotic stresses, directing resources towards stress responses and suppressing growth. Here we show that the primary metabolic response of Arabidopsis thaliana plants to high light or heat stress is different than that of plants subjected to a combination of high light and heat stress. We further demonstrate that a combination of high light and heat stress results in a unique metabolic response that includes increased accumulation of sugars and amino acids, coupled with decreased levels of metabolites participating in the tricarboxylic acid (TCA) cycle. Among the amino acids exclusively accumulated during a combination of high light and heat stress, we identified the non-proteinogenic amino acid {gamma}-aminobutyric acid (GABA). Analysis of different mutants deficient in GABA biosynthesis, in particular two independent alleles of glutamate decarboxylase 3 (gad3), reveal that GABA plays a key role in the acclimation of plants to a combination of high light and heat stress. Taken together, our findings identify a new role for GABA in regulating plant responses to stress combination. One sentence summaryThe non-proteinogenic amino acid {gamma}-aminobutyric acid (GABA) is required for plant acclimation to a combination of high light and heat stress in Arabidopsis.

plant biology↗

bioRxiv2020

PYL8 ABA receptors of Phoenix dactylifera play a crucial role in response to abiotic stress and are stabilized by ABA

The identification of those prevailing ABA receptors and molecular mechanisms that trigger drought adaptation in crops well adapted to harsh conditions such as date palm (Phoenix dactylifera, Pd) sheds light on plant-environment interactions. We reveal that PdPYL8-like receptors are predominantly expressed under abiotic stress, being Pd27 the most expressed receptor in date palm. Therefore, subfamily I PdPYL8-like receptors have been selected for ABA signaling during abiotic stress response in this crop. Biochemical characterization of PdPYL8-like and PdPYL1-like receptors revealed receptor- and ABA-dependent inhibition of PP2Cs, which triggers activation of the pRD29B-LUC reporter in response to ABA. PdPYLs efficiently abolish PP2C-mediated repression of ABA signaling, but loss of the Trp lock in the seed-specific AHG1-like phosphatase PdPP2C79 markedly impairs its inhibition by ABA receptors. Characterization of Arabidopsis transgenic plants that express PdPYLs shows enhanced ABA signaling in seed, root and guard cells. Specifically, Pd27 overexpressing (OE) plants showed lower ABA content and were more efficient than wild type to lower transpiration at negative soil water potential, leading to enhanced drought tolerance. Finally, PdPYL8-like receptors accumulate after ABA treatment, which suggests that ABA-induced stabilization of these receptors operates in date palm for efficient boosting of ABA signaling in response to abiotic stress. HighlightDate palm response to abiotic stress is triggered through PYL8-like ABA receptors that are stabilized by the hormone, which boosts plant adaptation to drought mediated by ABA.

plant biology↗

bioRxiv2020

The generalist herbivore Tetranychus urticae (Koch) adapts to novel plant hosts through rapid evolution of metabolic resistance

Genetic adaptation, occurring over a long evolutionary time, enables host-specialized herbivores to develop novel resistance traits and to efficiently counteract the defenses of a narrow range of host plants. In contrast, physiological acclimation, leading to the suppression and/or detoxification of host defenses is hypothesized to enable broad-generalists to shift between plant hosts. However, the host adaptation mechanisms used by generalists composed of host-adapted populations are not known. Tetranychus urticae is an extreme generalist herbivore whose individual populations perform well only on a subset of potential hosts. We combined experimental evolution, Arabidopsis genetics, mite reverse genetics, and pharmacological approaches to examine mite host adaptation upon the shift of a bean-adapted population to Arabidopsis thaliana. We showed that cytochrome P450 monooxygenases are required for mite adaptation to Arabidopsis. We identified activities of two tiers of P450s: general xenobiotic-responsive P450s that have a limited contribution to mite adaptation to Arabidopsis and adaptation-associated P450s that efficiently counteract Arabidopsis defenses. In {approx}25 generations of mite selection on Arabidopsis plants, mites evolved highly efficient detoxification-based adaptation, characteristic of specialist herbivores. This demonstrates that specialization to plant resistance traits can occur within the ecological timescale, enabling the two-spotted spider mite to shift to novel plant hosts.

evolutionary biology↗