The applications of CRISPR/Cas-mediated microRNA and lncRNA editing in plant biology: shaping the future of plant non-coding RNA research.

MAIN CONCLUSION: CRISPR/Cas technology has greatly facilitated plant non-coding RNA (ncRNA) biology research, establishing itself as a promising tool for ncRNA functional characterization and ncRNA-mediated plant improvement. Throughout the last decade, the promising genome editing tool clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated proteins (Cas; CRISPR/Cas) has allowed unprecedented advances in the field of plant functional genomics and crop improvement. Even though CRISPR/Cas-mediated genome editing system has been widely used to elucidate the biological significance of a number of plant protein-coding genes, this technology has been barely applied in the functional analysis of those non-coding RNAs (ncRNAs) that modulate gene expression, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Nevertheless, compelling findings indicate that CRISPR/Cas-based ncRNA editing has remarkable potential for deciphering the biological roles of ncRNAs in plants, as well as for plant breeding. For instance, it has been demonstrated that CRISPR/Cas tool could overcome the challenges associated with other approaches employed in functional genomic studies (e.g., incomplete knockdown and off-target activity). Thus, in this review article, we discuss the current status and progress of CRISPR/Cas-mediated ncRNA editing in plant science in order to provide novel prospects for further assessment and validation of the biological activities of plant ncRNAs and to enhance the development of ncRNA-centered protocols for crop improvement.

Growth, Survival and Biomass Production of Barley in a Polluted Mine Soil Amended with Biochar and Animal Manure.

In the present study, sheep manure (0%, 10% and 20% w/w) and biochar derived from coniferous tree woods (0%, 2.5% and 5% w/w) were incorporated into a multi-MTE contaminated soil from a former iron mine site and incubated for 10 days. A seeds of barley were grown in the amended soil and different morphological traits were measured after 30 days. Results indicated that MTE stress reduced the shoot length, stem diameter, leaf area, number of leaves and dry biomass as compared to the control. Organic amendments application increased soil pH and was found to affect significantly almost all the measured parameters. Animal manure was found effective in improvement of the morphological characteristics of barley plants comparing to biochar amendments. Our results suggested that animal manure could be used for reducing the effect of MTE on the morphological proprieties of barley grown in a former iron mine soil.

A Fruitful Decade Using Synthetic Promoters in the Improvement of Transgenic Plants.

Advances in plant biotechnology provide various means to improve crop productivity and greatly contributing to sustainable agriculture. A significant advance in plant biotechnology has been the availability of novel synthetic promoters for precise spatial and temporal control of transgene expression. In this article, we review the development of various synthetic promotors and the rise of their use over the last several decades for regulating the transcription of various transgenes. Similarly, we provided a brief description of the structure and scope of synthetic promoters and the engineering of their cis-regulatory elements for different targets. Moreover, the functional characteristics of different synthetic promoters, their modes of regulating the expression of candidate genes in response to different conditions, and the resulting plant trait improvements reported in the past decade are discussed.

Characterization of plant growth promoting rhizobacteria and their benefits on growth and phosphate nutrition of faba bean and wheat.

In recent years, more attention has been paid to plant growth promoting (PGP) rhizobacteria use as a biofertilizer alternative to chemical fertilizers, which might cause damage to the environment. The main objective of this work was to evaluate the field application of PGP bacteria and rhizobial strains on the productivity of two food crops extensively used in Morocco; Vicia faba L. and Triticum durum L. A field experiment with four treatments was designed: (1) control without inoculation, (2) PGP bacteria alone (P), (3) rhizobia alone (R) and (4) a mixture of PGP-rhizobia (PR). Furthermore, the PGP strains were tested for their ability to solubilize complex mineral phosphorus and potassium and for their production of indole acetic acid and exopolysaccharides. The strains showed several plant growth promoting traits. Field inoculation by these rhizobacteria improved phosphorus uptake and the agronomic parameters of faba bean and wheat plants, such as biomass of shoots and roots, as well as the weight of bean pods and wheat spikes. The most pronounced effect was displayed by rhizobial strains or the combination of PGP-rhizobia. The rhizobacterial inoculation significantly stimulated the growth of both crops and could be used as potential biofertilizers to optimize growth and phosphorus retention capacity.

The impact of molecular genetics in plant breeding: realities and perspectives / El impacto de la genética molecular en el mejoramiento genético vegetal: realidades y perspectivas

Even when conventional breeding was effective in achieving a continuous improvement in yield, Molecular Genetics tools applied in plant breeding contributed to maximize genetic gain. Thus, the use of DNA technology applied in agronomic improvement gave rise to Molecular Breeding, discipline which groups the different breeding strategies where genotypic selection, based on DNA markers, are used in combination with or in replacement of phenotypic selection. These strategies can be listed as: marker-assisted selection; marker-assisted backcrossing; marker assisted recurrent selection; and genomic selection. Strong arguments have been made about the potential advantages that Molecular Breeding brings, although little has been devoted to discussing its feasibility in practical applications. The consequence of the lack of a deep analysis when implementing a strategy of Molecular Breeding is its failure, leading to many undesirable outcomes and discouraging breeders from using the technology. The aim of this work is to trigger a debate about the convenience of the use of Molecular Breeding strategies in a breeding program considering the DNA technology of choice, the complexity of the trait of agronomic interest to be improved, the expected accuracy in the selection, and the demanded resources.

El mejoramiento convencional ha sido efectivo para lograr una mejora continua en el rendimiento; sin embargo las herramientas de Genética Molecular aplicadas en el fitomejoramiento han contribuido a maximizar la ganancia genética. Es así que el uso de la tecnología de ADN aplicada en la mejora agronómica dio lugar al Mejoramiento Molecular, disciplina que agrupa las diferentes estrategias en las que la selección genotípica, basada en marcadores de ADN, es utilizada en combinación con, o bien en reemplazo de, la selección fenotípica. Estas estrategias se pueden clasificar como: selección asistida por marcadores; retrocruzamiento asistido por marcadores; selección recurrente asistida por marcadores; y selección genómica. Se han presentado fuertes argumentos sobre las potenciales ventajas que aporta el mejoramiento molecular, aunque poco se ha dedicado a discutir la viabilidad de su aplicación práctica. La consecuencia de la falta de un análisis profundo al implementar una estrategia de este tipo puede ser su fracaso, lo que puede derivar en resultados indeseables, desalentando a los fitomejoradores a usar la tecnología. El objetivo de este trabajo es propiciar un debate sobre la conveniencia del uso práctico de estrategias de mejoramiento molecular teniendo en cuenta la tecnología de ADN elegida, la complejidad del rasgo de interés agronómico que se quiere mejorar, la precisión esperada en la selección y los recursos demandados.

Phosphorus: The Underrated Element for Feeding the World.

Predictions on the lifetime of phosphate (Pi) reserves usually take into account only the need for crop production. A recent report predicts the global need of chemical Pi fertilizer for sustaining productivity in cropland and grassland. Here we discuss the implications of these predictions for the lifetime of Pi reserves.

Reflexo da interação genótipo x ambiente sobre o melhoramento genético de feijão / Reflex of genotype x environment interaction on the genetic improvement of bean

RESUMO: O objetivo foi avaliar os componentes da variância fenotípica e estimar a influência da interação genótipo*ambiente no rendimento de grãos em feijão. Os componentes da variância fenotípica foram estimados pelo método da máxima verossimilhança restrita e do melhor preditor linear não viesado (REML/BLUP), juntamente com o espaço de inferência específico. As avaliações foram realizadas nas safras agrícolas de 2006/07 a 2011/12 no município de Lages/SC. Durante o período, 104 genótipos foram avaliados. Os dados são desbalanceados, sendo que 13 genótipos permaneceram nos ensaios em todos os anos. Observando os resultados, foi possível visualizar que a grande variação (59,0%) no comportamento dos genótipos ao longo dos anos é atribuída principalmente à variância do ambiente (σ2a=436.245). Houve diferença significativa entre genótipos para todos os ambientes. Porém, a diferença entre eles foi constante, ou seja, os genótipos não responderam de modo diferenciado frente aos ambientes. A interação genótipo*ambiente (σ2ga=1.368) responde preponderantemente por uma ínfima alteração (0,2%) na variação fenotípica, não discriminando de genótipos de feijão quanto ao rendimento de grãos em Lages/SC. Este fato favorece programas de melhoramento vegetal, onde a interação genótipo*ambiente poderia dificultar a distinção, seleção e recomendação de constituições genotípicas superiores. Nessa situação, processos de recomendação de cultivares (ensaio de valor de cultivo e uso - VCU) que mantenham os mesmos genótipos dispensam avaliações sucessivas, pois o ranqueamento é paralelo no decorrer dos anos.

ABSTRACT: The objective of this research was to evaluate the phenotypic variance components and estimate the influence of interaction genotype*environment in grain yield of beans. The variance components were estimated by the method restricted maximum likelihood and best linear unbiased prediction (REML / BLUP), along with the specific space of inference. Data were collected during the crop seasons 2006/07 to 2011/12 in Lages, SC - Brazil. During this period, 104 genotypes were evaluated. The data are unbalanced and 13 genotypes remained presents in all the assays years. Observing the results it was possible to see that the large variation (59.0%) in the performance of genotypes over the years is primarily attributable to the variance of the environment (σ2a=436245). There were significant differences among genotypes for all environments, but the difference between them were constant, ie, the genotypes did not respond differently in environments. Genotype*environment responds primarily by very small changes (0.2%) in the phenotypic variation (σ2ga=1368), with no parameters to discriminate the grain yield of genotypes in Lages, SC - Brazil. This fact makes easier the selection in plant breeding programs, where interaction genotype*environment could hinder distinction and selection of superior genotypic constitutions. In this situation, the processes of recommendation from improved lines (assay value for cultivation and use - VCU) that maintain the same genotypes dispense successive evaluations, since the ranking is parallel over the years.