Role of salicylic acid in acclimation to low temperature

Low temperature is one of the most important limiting factors for plant growth throughout the world. Exposure to low temperature may cause various phenotypic and physiological symptoms, and may result in oxidative stress, leading to loss of membrane integrity and to the impairment of photosynthesis and general metabolic processes. Salicylic acid (SA),phenolic compound produced by a wide range of plant species, a may participate in many physiological and metabolic reactions in plants. It has been shown that exogenous SA may provide protection against low temperature injury in various plant species, while various stress factors may also modify the synthesis and metabolism of SA. In the present review, recent results on the effects of SA and related compounds in processes leading to acclimation to low temperatures will be discussed

Plant cell culture technology in the cosmetics and food industries : current state and future trends

The production of drugs, cosmetics, and food which are derived from plant cell and tissue cultures has a long tradition. The emerging trend of manufacturing cosmetics and food products in a natural and sustainable manner has brought a new wave in plant cell culture technology over the past 10 years. More than 50 products based on extracts from plant cell cultures have made their way into the cosmetics industry during this time, whereby the majority is produced with plant cell suspension cultures. In addition, the first plant cell culture-based food supplement ingredients, such as Echigena Plus and Teoside 10, are now produced at production scale. In this mini review, we discuss the reasons for and the characteristics as well as the challenges of plant cell culture-based productions for the cosmetics and food industries. It focuses on the current state of the art in this field. In addition, two examples of the latest developments in plant cell culture-based food production are presented, that is, superfood which boosts health and food that can be produced in the lab or at home

A genomic catalog of Earth’s microbiomes

The reconstruction of bacterial and archaeal genomes from shotgun metagenomes has enabled insights into the ecology and evolution of environmental and host-associated microbiomes. Here we applied this approach to >10,000 metagenomes collected from diverse habitats covering all of Earth’s continents and oceans, including metagenomes from human and animal hosts, engineered environments, and natural and agricultural soils, to capture extant microbial, metabolic and functional potential. This comprehensive catalog includes 52,515 metagenome-assembled genomes representing 12,556 novel candidate species-level operational taxonomic units spanning 135 phyla. The catalog expands the known phylogenetic diversity of bacteria and archaea by 44% and is broadly available for streamlined comparative analyses, interactive exploration, metabolic modeling and bulk download. We demonstrate the utility of this collection for understanding secondary-metabolite biosynthetic potential and for resolving thousands of new host linkages to uncultivated viruses. This resource underscores the value of genome-centric approaches for revealing genomic properties of uncultivated microorganisms that affect ecosystem processes

A genomic catalog of Earth’s microbiomes

The reconstruction of bacterial and archaeal genomes from shotgun metagenomes has enabled insights into the ecology and evolution of environmental and host-associated microbiomes. Here we applied this approach to >10,000 metagenomes collected from diverse habitats covering all of Earth’s continents and oceans, including metagenomes from human and animal hosts, engineered environments, and natural and agricultural soils, to capture extant microbial, metabolic and functional potential. This comprehensive catalog includes 52,515 metagenome-assembled genomes representing 12,556 novel candidate species-level operational taxonomic units spanning 135 phyla. The catalog expands the known phylogenetic diversity of bacteria and archaea by 44% and is broadly available for streamlined comparative analyses, interactive exploration, metabolic modeling and bulk download. We demonstrate the utility of this collection for understanding secondary-metabolite biosynthetic potential and for resolving thousands of new host linkages to uncultivated viruses. This resource underscores the value of genome-centric approaches for revealing genomic properties of uncultivated microorganisms that affect ecosystem processes

Microdissection of Shoot Meristem Functional Domains

The shoot apical meristem (SAM) maintains a pool of indeterminate cells within the SAM proper, while lateral organs are initiated from the SAM periphery. Laser microdissection–microarray technology was used to compare transcriptional profiles within these SAM domains to identify novel maize genes that function during leaf development. Nine hundred and sixty-two differentially expressed maize genes were detected; control genes known to be upregulated in the initiating leaf (P0/P1) or in the SAM proper verified the precision of the microdissections. Genes involved in cell division/growth, cell wall biosynthesis, chromatin remodeling, RNA binding, and translation are especially upregulated in initiating leaves, whereas genes functioning during protein fate and DNA repair are more abundant in the SAM proper. In situ hybridization analyses confirmed the expression patterns of six previously uncharacterized maize genes upregulated in the P0/P1. P0/P1-upregulated genes that were also shown to be downregulated in leaf-arrested shoots treated with an auxin transport inhibitor are especially implicated to function during early events in maize leaf initiation. Reverse genetic analyses of asceapen1 (asc1), a maize D4-cyclin gene upregulated in the P0/P1, revealed novel leaf phenotypes, less genetic redundancy, and expanded D4-CYCLIN function during maize shoot development as compared to Arabidopsis. These analyses generated a unique SAM domain-specific database that provides new insight into SAM function and a useful platform for reverse genetic analyses of shoot development in maize

Advances in entomopathogen isolation: a case of bacteria and fungi

Entomopathogenic bacteria and fungi are quite frequently found in soils and insect cadavers. The first step in utilizing these microbes as biopesticides is to isolate them, and several culture media and insect baiting procedures have been tested in this direction. In this work, the authors review the current techniques that have been developed so far, in the last five decades, and display brief protocols which can be adopted for the isolations of these entomopathogens. Among bacteria, this review focuses on Serratia spp. and bacteria from the class Bacilli. Among fungi, the review focuses those from the order Hypocreales, for example, genera Beauveria, Clonostachys, Lecanicillium, Metarhizium, and Purpureocillium. The authors chose these groups of entomopathogenic bacteria and fungi based on their importance in the microbial biopesticide market

Heterosis en el proceso germinativo y en caracteres de semilla del hí-brido de maíz (Zea mays L.) HAZUL 10E

Objective: To quantify the heterosis in physical and physiological characteristics of seeds of the simple and trilineal crosses of the maize hybrid HAZUL 10E. Methodology: Seeds of the genotypes that make up the HAZUL 10E maize hybrid (inbred lines and simple and trilineal crosses) were used. The experimental design was completely randomized with three repetitions. Physical characteristics of the seeds (weight, width, thickness, length, volume, density and the ratios width/length of seed and thickness/length of seed) and physiological (normal and abnormal seedlings, inert seeds, and lengths and dry matter of plumule, radicle and total) were evaluated. Heterosis and heterobeltiosis were determined and their differences between both crosses were tested with Student's t test. Results: Heterosis and heterobeltiosis were higher in the single cross than in the trilineal one. In the single cross, the higher values of both heterosis corresponded to plumule, radicle and total dry matter; followed by weight and seed volume. In the trilinear, the highest values corresponded to normal seedlings and radicle length and biomass, and total. The determining variables of the shape, the formation of normal seedlings and the elongation of the radicle, responded better to hybridization in the trilineal cross. Study limitations: None presented. Conclusions: In the single cross, heterosis increased the seed size and the biomass accumulated in the seedlings; while in the trilineal cross, it affected the shape of the seed and the seedlings produced

First Report of Powdery Mildew (Pseudoidium anacardii) of Mango Trees in Sinaloa, Mexico

Powdery mildew of mango is an important disease in Mexico's northern Sinaloa state. Identification of the causal fungal agent has been hindered by the absence of information regarding its teleomorph, as well as a detailed morphometric analysis of the anamorph and molecular characterization. The first symptoms of the disease appear in mango inflorescences of early February, and it subsequently affects young fruits. The disease progresses during March and early April, causing significant fruit abortion and a scabby appearance in a high percentage of fruits that remain attached to the trees. We observed the disease on inflorescences but not in leaves during our sampling period. Powdery mildew specimens were collected during 2011 and 2012 and included Kent and Keith varieties from commercial orchards, and creole materials from backyards of private residences in the Ahome and Fuerte Counties of northern Sinaloa, Mexico. Symptomatic inflorescences were analyzed morphologically. Conidiophores and conidia were prepared by touching the whitish lesions with clear adhesive tape, which was then placed over microscope slides with a drop of distilled water and observed under a compound microscope. The anamorph structures of the pathogen were measured. The mycelium was septate and ramified on the surface of the host, forming a dense coat of branching hyphae. The mycelium had a diameter of 2.5 to 8.7 μm; conidiophores (Pseudoidium type) emerged from the superficial mycelium, were unbranched, and consisted of 1 to 3 cells with conidia forming singly from the apex. The length of the conidiophores varied from 30.0 to 77.5 μm; the foot cell of the conidiophores was straight, 10.0 to 47.5 μm long and with a diameter of 5.0 to 15.5 μm across its midpoint. Conidia without fibrosin bodies were borne singly, and were ellipsoid/ovoid, 22.5 to 46.2 μm long and 15.0 to 27.5 μm wide. Eighty percent of the germ tubes were forked (lobed); the rest were simple, emerged from the end, and were occasionally on the side of the conidia. Germ tubes ranged from 2.0 to 7.2 μm at the midpoint. The surface of the conidia appeared smooth under the scanning electron microscope, and elliptical conidia appeared constricted at their ends; this, however, was not observed in the ovoid conidia. In both cases, the terminal end of the conidia was smooth. The teleomorph was not found. Molecular and phylogenetic analysis of the ITS rDNA (2) region showed that samples are closely related to specimens of Pseudoidium anacardii (1) (teleomorph: Erysiphe quercicola [4]) collected from mango trees in diverse countries. Measurements of somatic and asexual structures are in agreement with descriptions of P. anachardii (formerly known as Oidium mangiferae) from India (3). The nucleotide sequences derived from this research were deposited in GenBank (Accession Nos. JX893951 to JX893957). To our knowledge, this is the first report of P. anacardii associated to mango inflorescences in Sinaloa, Mexico. Due to the economic importance of powdery mildew of mango trees in Sinaloa, future research directions should focus on finding the teleomorph of the fungus to support its identity