Gene network downstream plant stress response modulated by peroxisomal H2O2

Reactive oxygen species (ROS) act as secondary messengers that can be sensed by specific redox-sensitive proteins responsible for the activation of signal transduction culminating in altered gene expression. The subcellular site, in which modifications in the ROS/oxidation state occur, can also act as a specific cellular redox network signal. The chemical identity of ROS and their subcellular origin is actually a specific imprint on the transcriptome response. In recent years, a number of transcriptomic studies related to altered ROS metabolism in plant peroxisomes have been carried out. In this study, we conducted a metaanalysis of these transcriptomic findings to identify common transcriptional footprints for plant peroxisomal-dependent signaling at early and later time points. These footprints highlight the regulation of various metabolic pathways and gene families, which are also found in plant responses to several abiotic stresses. Major peroxisomal-dependent genes are associated with protein and endoplasmic reticulum (ER) protection at later stages of stress while, at earlier stages, these genes are related to hormone biosynthesis and signaling regulation. Furthermore, in silico analyses allowed us to assign human orthologs to some of the peroxisomal-dependent proteins, which are mainly associated with different cancer pathologies. Peroxisomal footprints provide a valuable resource for assessing and supporting key peroxisomal functions in cellular metabolism under control and stress conditions across species.Spanish Ministry of Science, Innovation and Universities (MCIU)State Research Agency (AEI)FEDER grant PGC2018-098372-B-I00MCIU Research Personnel Training (FPI) grant BES-2016-07651

The transcriptome of soybean reproductive tissues subjected to water deficit, heat stress, and a combination of water deficit and heat stress

Global warming and climate change are driving an alarming increase in the frequency and intensity of extreme climate events, such as droughts, heat waves, and their combination, inflicting heavy losses to agricultural production. Recent studies revealed that the transcriptomic responses of different crops to water deficit (WD) or heat stress (HS) are very different from that to a combination of WD + HS. In addition, it was found that the effects of WD, HS, and WD + HS are significantly more devastating when these stresses occur during the reproductive growth phase of crops, compared to vegetative growth. As the molecular responses of different reproductive and vegetative tissues of plants to WD, HS, or WD + HS could be different from each other and these differences could impact many current and future attempts to enhance the resilience of crops to climate change through breeding and/or engineering, we conducted a transcriptomic analysis of different soybean (Glycine max) tissues to WD, HS, and WD + HS. Here we present a reference transcriptomic dataset that includes the response of soybean leaf, pod, anther, stigma, ovary, and sepal to WD, HS, and WD + HS conditions. Mining this dataset for the expression pattern of different stress response transcripts revealed that each tissue had a unique transcriptomic response to each of the different stress conditions. This finding is important as it suggests that enhancing the overall resilience of crops to climate change could require a coordinated approach that simultaneously alters the expression of different groups of transcripts in different tissues in a stress-specific manner

Función de la peroxina PEX11a en la interacción planta-patógeno

Comunicación de congreso presentada en: II Jornada de la Juventud Investigadora. Granada, España. 18 octubre (2023

Jasmonic acid is required for tomato acclimation to multifactorial stress combination

As a result of global warming and climate change, the number and intensity of weather events such as droughts, heat waves, and floods are increasing, resulting in major losses in crop yield worldwide. Combined with the accumulation of different pollutants, this situation is leading to a gradual increase in the complexity of environmental factors affecting plants. We recently used the term ‘multifactorial stress combination’ (MFSC) to describe the impact of three or more stressors occurring simultaneously or sequentially on plants. Here, we show that a MFSC of six different abiotic stressors (high light, heat, nitrogen deficiency, paraquat, cadmium, and salinity) has a negative impact on the growth, photosystem II function, and photosynthetic activity of mature tomato plants. We further reveal a negative correlation between proline accumulation and the increasing number of stress factors combined, suggesting that proline could have an adverse effect on plants during MFSC. Our findings further indicate that alterations in hormonal levels and stomatal responses are stress/stress combination-dependent, and that a tomato mutant deficient in jasmonic acid accumulation is more sensitive to high light and its combinations with salinity and/or paraquat. Taken together, our study reveals that the effects of MFSC on tomato plants are broad, that photosynthesis and proline accumulation are especially vulnerable to MFSC, and that jasmonic acid is required for tomato acclimation to MFSCs involving high light, salinity and paraquat.Funding for open access charge: CRUE-Universitat Jaume

ROS and redox regulation of cell-to-cell and systemic signaling in plants during stress

Stress results in the enhanced accumulation of reactive oxygen species (ROS) in plants, altering the redox state of cells and triggering the activation of multiple defense and acclimation mechanisms. In addition to activating ROS and redox responses in tissues that are directly subjected to stress (termed 'local' tissues), the sensing of stress in plants triggers different systemic signals that travel to other parts of the plant (termed 'systemic' tissues) and activate acclimation and defense mechanisms in them; even before they are subjected to stress. Among the different systemic signals triggered by stress in plants are electric, calcium, ROS, and redox waves that are mobilized in a cell-to-cell fashion from local to systemic tissues over long distances, sometimes at speeds of up to several millimeters per second. Here, we discuss new studies that identified various molecular mechanisms and proteins involved in mediating systemic signals in plants. In addition, we highlight recent studies that are beginning to unravel the mode of integration and hierarchy of the different systemic signals and underline open questions that require further attention. Unraveling the role of ROS and redox in plant stress responses is highly important for the development of climate resilient crops

Nitric Oxide and Globin Glb1 Regulate Fusarium oxysporum Infection of Arabidopsis thaliana

Plants continuously interact with fungi, some of which, such as Fusarium oxysporum, are lethal, leading to reduced crop yields. Recently, nitric oxide (NO) has been found to play a regulatory role in plant responses to F. oxysporum, although the underlying mechanisms involved are poorly understood. In this study, we show that Arabidopsis mutants with altered levels of phytoglobin 1 (Glb1) have a higher survival rate than wild type (WT) after infection with F. oxysporum, although all the genotypes analyzed exhibited a similar fungal burden. None of the defense responses that were analyzed in Glb1 lines, such as phenols, iron metabolism, peroxidase activity, or reactive oxygen species (ROS) production, appear to explain their higher survival rates. However, the early induction of the PR genes may be one of the reasons for the observed survival rate of Glb1 lines infected with F. oxysporum. Furthermore, while PR1 expression was induced in Glb1 lines very early on the response to F. oxysporum, this induction was not observed in WT plants

Peroxisomes: a redox-signaling node in intracellular communication and stress response

Conferencia invitada presentada en: XX Congreso de la Sociedad española de Biología celular. Córdoba, España, 13-15 noviembre (2023