Resiliencia de la cobertura vegetal en el Suroeste de México ante los efectos del cambio climático

The scenarios modeling of climate changes using geographic information systems to estimate the vegetation cover resilience is a useful tool to project future impacts and implement conservation or management strategies. We associate spatially the biodiversity of the vegetation cover of Southwest Mexico with its ability to adapt to the effects of climate change. We analysis this association estimating species richness and diversity indices, and its relationship with scenarios of future climate. Geographical records of the National Forest and Soil Inventory were obtained for eight plant communities (arboreal, shrubby, herbaceous, palm, cactus, vines, ferns, and xerophyte) distributed in Guerrero, Oaxaca, and Chiapas. The climatic projection was to 2050, with global circulation A2 models (CCCMA, HADCM3 and CSIRO average), 19 bioclimatic variables and a resolution of 2.5 minutes. Climate change scenarios were modelled with the MaxEnt algorithm and species richness, diversity index, and spatial regressions with Diva-GIS v7.5 software. The spatial regression models estimated that higher richness and species diversity, the greater resilience that the ecosystem would show. The cactus, palm, and xerophytic plant communities presented greater vulnerability to climate change. Variations in temperature seasonality turned out to be the factor that would condition its future distribution. Therefore, in conservation or management strategies, diversity should be considered as an agent of the ecosystem that cushions the negative effects of future climate.El modelado de escenarios de cambios climáticos utilizando sistemas de información geográfica para estimar la resiliencia de la cobertura vegetal es una herramienta útil para proyectar impactos futuros e implementar estrategias de conservación o manejo. En el presente trabajo asociamos espacialmente la biodiversidad de la cobertura vegetal del Suroeste de México con su capacidad para adaptarse a los efectos del cambio climático. Para analizar esta asociación se estimaron índices de riqueza y diversidad de especies, y su relación con escenarios de clima futuro. Se utilizaron los registros geográficos del Inventario Nacional Forestal y de Suelos para ocho comunidades vegetales (arbórea, arbustiva, herbácea, palma, cactus, bejucos, helechos y xerófita) distribuidas entre Guerrero, Oaxaca y Chiapas. La proyección climática fue al 2050, con modelos de circulación global A2 (promedio CCCMA, HADCM3 y CSIRO), 19 variables bioclimáticas y una resolución de 2.5 minutos. Los escenarios de cambio climático se modelaron con el algoritmo MaxEnt y la riqueza de especies, índice de diversidad y regresiones espaciales con el software Diva-GIS v7.5. Los modelos de regresión espacial estimaron que a mayor riqueza y diversidad de especies mayor seria la resiliencia que mostraría el ecosistema. Las comunidades vegetales cactus, palma y xerófita mostraron mayor vulnerabilidad al cambio climático. Las variaciones en la estacionalidad de la temperatura resultó ser el factor que condicionaría su distribución futura. Por lo que, las estrategias de conservación o manejo deberían considerar a la diversidad como un agente del ecosistema que amortiguaría a los efectos negativos del clima futuro

The novel and taxonomically restricted Ah24 gene from grain amaranth (Amaranthus hypochondriacus) has a dual role in development and defense

Grain amaranths tolerate stress and produce highly nutritious seeds. We have identified several (a)biotic stress-responsive genes of unknown function in Amaranthus hypochondriacus, including the so-called Ah24 gene. Ah24 was expressed in young or developing tissues; it was also strongly induced by mechanical damage, insect herbivory and methyl jasmonate and in meristems and newly emerging leaves of severely defoliated plants. Interestingly, an in silico analysis of its 1304 bp promoter region showed a predominance of regulatory boxes involved in development, but not in defense. The Ah24 cDNA encodes a predicted cytosolic protein of 164 amino acids, the localization of which was confirmed by confocal microscopy. Additional in silico analysis identified several other Ah24 homologs, present almost exclusively in plants belonging to the Caryophyllales. The possible function of this gene in planta was examined in transgenic Ah24 overexpressing Arabidopsis thaliana and Nicotiana tabacum plants. Transformed Arabidopsis showed enhanced vegetative growth and increased leaf number with no penalty in one fitness component, such as seed yield, in experimental conditions. Transgenic tobacco plants, which grew and reproduced normally, had increased insect herbivory resistance. Modified vegetative growth in transgenic Arabidopsis coincided with significant changes in the expression of genes controlling phytohormone synthesis or signaling, whereas increased resistance to insect herbivory in transgenic tobacco coincided with higher jasmonic acid and proteinase inhibitor activity levels, plus the accumulation of nicotine and several other putative defense-related metabolites. It is proposed that the primary role of the Ah24 gene in A. hypochondriacus is to contribute to a rapid recovery post-wounding or defoliation, although its participation in defense against insect herbivory is also plausible

Unravelling Chemical Composition of Agave Spines: News from Agave fourcroydes Lem.

Spines are key plant modifications developed to deal against herbivores; however, its physical structure and chemical composition have been little explored in plant species. Here, we took advantage of high-throughput chromatography to characterize chemical composition of Agave fourcroydes Lem. spines, a species traditionally used for fiber extraction. Analyses of structural carbohydrate showed that spines have lower cellulose content than leaf fibers (52 and 72%, respectively) but contain more than 2-fold the hemicellulose and 1.5-fold pectin. Xylose and galacturonic acid were enriched in spines compared to fibers. The total lignin content in spines was 1.5-fold higher than those found in fibers, with elevated levels of syringyl (S) and guaiacyl (G) subunits but similar S/G ratios within tissues. Metabolomic profiling based on accurate mass spectrometry revealed the presence of phenolic compounds including quercetin, kaempferol, (+)-catechin, and (-)-epicatechin in A. fourcroydes spines, which were also detected in situ in spines tissues and could be implicated in the color of these plants' structures. Abundance of (+)-catechins could also explain proanthocyanidins found in spines. Agave spines may become a plant model to obtain more insights about cellulose and lignin interactions and condensed tannin deposition, which is valuable knowledge for the bioenergy industry and development of naturally dyed fibers, respectively

Ectopic callose deposition into woody biomass modulates the nano-architecture of macrofibrils

Plant biomass plays an increasingly important role in the circular bioeconomy, replacing non-renewable fossil resources. Genetic engineering of this lignocellulosic biomass could benefit biorefinery transformation chains by lowering economic and technological barriers to industrial processing. However, previous efforts have mostly targeted the major constituents of woody biomass: cellulose, hemicellulose and lignin. Here we report the engineering of wood structure through the introduction of callose, a polysaccharide novel to most secondary cell walls. Our multiscale analysis of genetically engineered poplar trees shows that callose deposition modulates cell wall porosity, water and lignin contents and increases the lignin-cellulose distance, ultimately resulting in substantially decreased biomass recalcitrance. We provide a model of the wood cell wall nano-architecture engineered to accommodate the hydrated callose inclusions. Ectopic polymer introduction into biomass manifests in new physico-chemical properties and offers new avenues when considering lignocellulose engineering.Bourdon et al. demonstrate the possibility to ectopically synthesize callose, a polymer restricted to primary cell walls, into Arabidopsis and aspen secondary cell walls to manipulate their ultrastructure and ultimately reduce their recalcitrance

Advances in Breeding, Bioprospecting, and In Vitro Culture of Laelia Orchid Species

Orchids (Orchidaceae) are plants that are highly appreciated by their beautiful flowers worldwide. Moreover, they represent a source of metabolites with applications in medicine and biotechnology. Within the Orchidaceae family, the Laelia genus is a group of orchid species from the Neotropics and is probably one of the most representative genera of America. Laelia orchids are cultivated by their splendid flowers and are widely used in orchid breeding. Here, we revise the use of the Laelia genus in orchid breeding and metabolite bioprospecting. We also analyze the use of plant tissue culture (PTC) as an alternative to conventional propagation and as a strategy for the recovery of those Laelia species threatened with extinction. We summarize and discuss the recent advances in the application of different PTC techniques for mass multiplication based on asymbiotic germination, organogenesis, protocorm-like bodies development, and somatic embryogenesis, and the advances of in vitro conservation by cryoconservation and the use of slow-growth promoting hormones. Finally, we suggest future directions and venues in research for Laelia species

Advances in Breeding, Bioprospecting, and In Vitro Culture of <i>Laelia</i> Orchid Species

Orchids (Orchidaceae) are plants that are highly appreciated by their beautiful flowers worldwide. Moreover, they represent a source of metabolites with applications in medicine and biotechnology. Within the Orchidaceae family, the Laelia genus is a group of orchid species from the Neotropics and is probably one of the most representative genera of America. Laelia orchids are cultivated by their splendid flowers and are widely used in orchid breeding. Here, we revise the use of the Laelia genus in orchid breeding and metabolite bioprospecting. We also analyze the use of plant tissue culture (PTC) as an alternative to conventional propagation and as a strategy for the recovery of those Laelia species threatened with extinction. We summarize and discuss the recent advances in the application of different PTC techniques for mass multiplication based on asymbiotic germination, organogenesis, protocorm-like bodies development, and somatic embryogenesis, and the advances of in vitro conservation by cryoconservation and the use of slow-growth promoting hormones. Finally, we suggest future directions and venues in research for Laelia species

Phage Therapy for Crops: Concepts, Experimental and Bioinformatics Approaches to Direct Its Application

Phage therapy consists of applying bacteriophages, whose natural function is to kill specific bacteria. Bacteriophages are safe, evolve together with their host, and are environmentally friendly. At present, the indiscriminate use of antibiotics and salt minerals (Zn2+ or Cu2+) has caused the emergence of resistant strains that infect crops, causing difficulties and loss of food production. Phage therapy is an alternative that has shown positive results and can improve the treatments available for agriculture. However, the success of phage therapy depends on finding effective bacteriophages. This review focused on describing the potential, up to now, of applying phage therapy as an alternative treatment against bacterial diseases, with sustainable improvement in food production. We described the current isolation techniques, characterization, detection, and selection of lytic phages, highlighting the importance of complementary studies using genome analysis of the phage and its host. Finally, among these studies, we concentrated on the most relevant bacteriophages used for biocontrol of Pseudomonas spp., Xanthomonas spp., Pectobacterium spp., Ralstonia spp., Burkholderia spp., Dickeya spp., Clavibacter michiganensis, and Agrobacterium tumefaciens as agents that cause damage to crops, and affect food production around the world

Bark water storage capacity influences epiphytic orchid preference for host trees

International audienc

Resiliencia de la cobertura vegetal en el Suroeste de México ante los efectos del cambio climático

https://revistasinvestigacion.unmsm.edu.pe/index.php/rpb/article/view/18187#:~:text=El%20modelado%20de,del%20clima%20futur

Non-Targeted Metabolomic Analysis of <i>Arabidopsis thaliana</i> (L.) Heynh: Metabolic Adaptive Responses to Stress Caused by N Starvation

As sessile organisms, plants develop the ability to respond and survive in changing environments. Such adaptive responses maximize phenotypic and metabolic fitness, allowing plants to adjust their growth and development. In this study, we analyzed the metabolic plasticity of Arabidopsis thaliana in response to nitrate deprivation by untargeted metabolomic analysis and using wild-type (WT) genotypes and the loss-of-function nia1/nia2 double mutant. Secondary metabolites were identified using seedlings grown on a hydroponic system supplemented with optimal or limiting concentrations of N (4 or 0.2 mM, respectively) and harvested at 15 and 30 days of age. Then, spectral libraries generated from shoots and roots in both ionization modes (ESI +/−) were compared. Totals of 3407 and 4521 spectral signals (m/z_rt) were obtained in the ESI+ and ESI− modes, respectively. Of these, approximately 50 and 65% were identified as differentially synthetized/accumulated. This led to the presumptive identification of 735 KEGG codes (metabolites) belonging to 79 metabolic pathways. The metabolic responses in the shoots and roots of WT genotypes at 4 mM of N favor the synthesis/accumulation of metabolites strongly related to growth. In contrast, for the nia1/nia2 double mutant (similar as the WT genotype at 0.2 mM N), metabolites identified as differentially synthetized/accumulated help cope with stress, regulating oxidative stress and preventing programmed cell death, meaning that metabolic responses under N starvation compromise growth to prioritize a defensive response