In this study we cloned a chitinase gene (SmchiC), from Serratia marcescens isolated from the corpse of a Diatraea magnifactella lepidopteran, which is an important sugarcane pest. The chitinase gene SmchiC amplified from the S. marcescens genome was cloned into the transformation vector p2X35SChiC and used to transform tobacco (Nicotiana tabacum L. cv Petit Havana SR1). The resistance of these transgenic plants to the necrotrophic fungus Botrytis cinerea and to the pest Spodoptera frugiperda was evaluated: both the activity of chitinase as well as the resistance against B. cinerea and S. frugiperda was significantly higher in transgenic plants compared to the wild-type.

Avocado fruits have a high nutritional value and economical importance at global level; however, anthracnose causes significant losses during the pre and postharvest stages. Fruits with anthracnose symptoms were monitored during June to July 2013 in Morelos, Mexico. Symptoms were showed in the exocarp of the fruits as circular brown-black spots. Besides, soft rot was observed in the mesocarp. Monoconidial isolates were grown on PDA. To confirm pathogenicity, eight healthy avocado fruits were inoculated with a 1 x 105 conidia.mL-1 suspension. First symptoms appeared three days after the inoculation and were similar to those observed in the field, while the control fruits were symptomless. The phytopathogenic fungus was reisolated from lesions to confirm the Koch’s postulated. The fungus was identified molecularly by sequencing internal transcribed spacer (ITS) region and a fragment of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. Both the sequences were deposited in GenBank (KP729610 and KP729611)...

White-rot fungi are efficient lignin degraders due to the secretion of lignin peroxidase, manganese peroxidase, laccase, and versatile peroxidase (VP) on decayed wood. The VP is a high-redox-potential enzyme and could be used to detoxify reactive oxygen species (ROS), which accumulate in plants during biotic and abiotic stresses. We cloned the VP gene and expressed it via the Agrobacterium transformation procedure in transgenic tobacco plants to assay their tolerance to different abiotic stress conditions. Thirty independent T₂ transgenic VP lines overexpressing the fungal Bjerkandera adustaVP gene were selected on kanamycin. The VP22, VP24, and VP27 lines showed significant manganese peroxidase (MnP) activity. The highest was VP22, which showed 10.87-fold more manganese peroxidase activity than the wild-type plants and led to a 34% increase in plant height and 28% more biomass. The VP22, VP24, and VP27 lines showed enhanced tolerance to drought, 200 mM NaCl, and 400 mM sorbitol. Also, these transgenics displayed significant tolerance to methyl viologen, an active oxygen-generating compound. The present data indicate that overproducing the VP gene in plants increases significantly their biomass and the abiotic stress tolerance. The VP enzyme is an effective biotechnological tool to protect organisms against ROS. In transgenic tobacco plants, it improves drought, salt, and oxidative stress tolerance. Thus, the VP gene represents a great potential for obtaining stress-tolerant crops.

Bacteria associated with plants, whether rhizospheric, epiphytic, or endophytic, play a crucial role in plant productivity and health by promoting growth through complex mechanisms known as plant growth promoters. This study aimed to isolate, characterize, identify, and evaluate the potential of endophytic bacteria from the resurrection plant Selaginella lepidophylla in enhancing plant growth, using Arabidopsis thaliana ecotype Col. 0 as a model system. Plant growth-promotion parameters were assessed on the bacterial isolates; this assessment included the quantification of indole-3-acetic acid, phosphate solubilization, and biological nitrogen fixation, a trehalose quantification, and the siderophore production from 163 endophytic bacteria isolated from S. lepidophylla. The bacterial genera identified included Agrobacterium, Burkholderia, Curtobacterium, Enterobacter, Erwinia, Pantoea, Pseudomonas, and Rhizobium. The plant growth promotion in A. thaliana was evaluated both in Murashige Skoog medium, agar-water, and direct seed inoculation. The results showed that the bacterial isolates enhanced primary root elongation and lateral root and root hair development, and increased the fresh and dry biomass. Notably, three isolates promoted early flowering in A. thaliana. Based on these findings, we propose the S. lepidophylla bacterial isolates as ideal candidates for promoting growth in other agriculturally important plants.

In this work, we report the draft genome sequence of Ensifer sp. P24N7, a symbiotic nitrogen-fixing bacterium isolated from nodules of Phaseolus vulgaris var. Negro Jamapa was planted in pots that contained mining tailings from Huautla, Morelos, México. The genomic DNA was sequenced by an Illumina NovaSeq 6000 using the 250 bp paired-end protocol obtaining 1,188,899 reads. An assembly generated with SPAdes v. 3.15.4 resulted in a genome length of 7,165,722 bp composed of 181 contigs with a N50 of 323,467 bp, a coverage of 76X, and a GC content of 61.96%. The genome was annotated with the NCBI Prokaryotic Genome Annotation Pipeline and contains 6631 protein-coding sequences, 3 complete rRNAs, 52 tRNAs, and 4 non-coding RNAs. The Ensifer sp. P24N7 genome has 59 genes related to heavy metal tolerance predicted by RAST server. These data may be useful to the scientific community because they can be used as a reference for other works related to heavy metals, including works in Huautla, Morelos.

The use of beneficial microorganisms in agriculture can increase the productivity of agricultural crops; however, there are few studies that consider aromatic plants, such as basil (Ocimum basilicum L.). The aim of this study was to evaluate the growth of 'Sweet Nufar' basil inoculated with arbuscular mycorrhizal fungi (AMF) and Azospirillum brasilense. The treatments tested were: 1) without microorganisms (control), 2) Rizhophagus intraradices, 3) Funneliformis mosseae, 4) AMF consortium, 5) Azospirillum brasilense, 6) R. intraradices + A. brasilense and 7) without microorganisms and irrigated with 100 % Steiner's nutrient solution. Treatments 1 to 6 were irrigated with the same nutrient solution, but at 50 %. Fifty days after transplanting, growth variables, mineral concentration, colonization percentage and number of AMF spores were recorded. The AMF and A. brasilense bacterium increased the fresh biomass weight and leaf area of 'Nufar' basil, which was associated with the highest concentration of nitrogen and potassium in the plant tissue. This implies that the microorganisms evaluated increase the development and growth of basil grown with reduced levels of mineral nutrition, which represents a sustainable alternative in the agronomic management of this crop under greenhouse conditions.