Medium 9781780647678

Plant Gene Silencing: Mechanisms and Applications. CABI Biotechnology Series 5

Views: 122
Ratings: (0)

Plant gene silencing is a crucially important phenomenon in gene expression and epigenetics. This book describes the way small RNA is produced and acts to silence genes, its likely origins in defence against viruses, and also its potential to improve plants. Plant gene silencing can be used to improve industrial traits, make plants more nutritious or more valuable to consumers, to remove allergens, and to improve resistance to weeds and pathogens.

List price: $140.00

Your Price: $112.00

You Save: 20%

Remix
Remove
 

11 Slices

Format Buy Remix

1: Diversity of RNA Silencing Pathways in Plants

PDF

1

Diversity of RNA Silencing

Pathways in Plants

Emilie Elvira-Matelot, Ángel Emilio Martínez de Alba and Hervé Vaucheret*

Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS,

Université Paris-Saclay, Versailles, France

1.1

Introduction

RNA silencing is a manifestation of eukaryote defences against exogenous invading nucleic acids. Indeed, infection by pathogens, including fungi, bacteria, viruses or viroids, generally results in the production of pathogen-specific short interfering

RNAs (siRNAs), the hallmark of RNA silencing (Hamilton and Baulcombe, 1999;

Navarro et  al., 2008). When loaded onto ARGONAUTE (AGO) proteins, these siRNAs guide the cleavage of the long RNAs naturally encoded by the invader

(Vaucheret, 2008). However, despite the highly sequence-specific effect of siRNAs, pathogen-derived RNAs generally are not eliminated because most pathogens encode proteins that counteract the biogenesis or the action of siRNAs (Pumplin and

 

2: Induction and Suppression of Silencing by Plant Viruses

PDF

2

Induction and Suppression of Silencing by Plant Viruses

Ares Mingot1, Adrian Valli2, Juan José López-Moya1,* and Juan Antonio García2,*

1

Centre for Research in Agricultural Genomics, Barcelona, Spain;

National Centre for Biotechnology, Madrid, Spain

2

2.1

Introduction

RNA silencing refers to an evolutionary conserved system that controls gene expression through sequence-specific mechanisms guided by small RNAs. This system is present in most eukaryotic organisms, playing important roles in different biological processes such as development, genome integrity and host defence against viruses and transposons (Siomi and Siomi, 2009).

The antiviral role of RNA silencing was discovered in plants (Hamilton and

Baulcombe, 1999), but it is also present in insects (Li et al., 2002), nematodes (Lu et al., 2005; Wilkins et al., 2005), fungi (Segers et al., 2007) and, under certain circumstances, it has also been proposed to be functional against viruses in mammals

 

3: Artificial Induction and Maintenance of Epigenetic Variations in Plants

PDF

3

Artiicial Induction and

Maintenance of Epigenetic

Variations in Plants

Soumita Das, Rahul Raj Singh and P.V. Shivaprasad*

National Centre for Biological Sciences, Bangalore, India

3.1

Introduction

The term ‘epigenetic’ was first coined in 1942 by Waddington, a British developmental biologist, referring to differentiation of cells from their totipotent state.

The term expresses the external manifestation of the genetic activity in organisms. Epigenetics has now emerged as a broad field of science that investigates a range of biological phenomena with novel molecular mechanisms. Epigenetics works on two levels – at the DNA level, and at the level of histones. Methylation of cytosines is context independent and reversible, and plays a crucial role especially if the modification is in the promoter regions of transcription units.

Cytosine methylation controls transposons and unruly elements in genomes. The second level of epigenetics is at the level of modifications of DNA-bound histone proteins. Many of the histone-modifying proteins have been characterized, although still many more remain to be discovered, and the sequence/priority order of the histone modifications are being elucidated. Among plants, small RNAs play an essential role in establishment and maintenance of DNA methylation, through a novel process termed ‘RNA directed DNA methylation’ (RdDM). In animals, the developmental programme is planned in the embryo; but in plants, it is designed post-embryonically through a poorly understood mechanism. Early indications are that epigenetic variations play a significant role in such programming. Thus, a case for epigenetic studies has been set, while the stepwise molecular events of such a phenomenon are largely unknown and currently an intense area of research.

 

4: Gene Silencing in Archaeplastida Algae

PDF

4

Gene Silencing in

Archaeplastida Algae

Xinrong Ma, Eun-Jeong Kim and Heriberto Cerutti*

School of Biological Sciences and Center for Plant Science

Innovation,University of Nebraska-Lincoln,Lincoln,USA

4.1

Introduction

Algae are a phylogenetically diverse group of aquatic eukaryotes, commonly comprising photosynthetic organisms found in marine, freshwater and even terrestrial systems. They play important roles in global carbon cycling and other ecosystem functions (Worden and Allen, 2010; Tirichine and Bowler, 2011). Recently, they have attracted interest due to their great potential as feedstock for the production of biofuels and biomaterials. In particular, microalgae are capable of harnessing sunlight and CO2 to synthesize many useful chemical compounds (Gimpel et al.,

2015; Guarnieri and Pienkos, 2015). However, despite the recent sequencing of several algal genomes, our knowledge of gene function and regulation in most algae is rather limited, constraining biotechnological advances and genetic engineering

 

5: Gene Silencing in Fungi: A Diversity of Pathways and Functions

PDF

5

Gene Silencing in Fungi:

A Diversity of Pathways and Functions

Santiago Torres-Martínez and Rosa M. Ruiz-Vázquez*

University of Murcia, Murcia, Spain

5.1

Introduction

Ribonucleic acids (RNAs) have emerged in the last two decades as key players in the complex networks of regulation of gene expression, with RNA-mediated gene silencing being one of the regulatory mechanisms often found in the eukaryotic world. RNA-mediated gene silencing has been referred to in different ways. Thus,

Napoli et al. (1990) first reported a phenomenon they called ‘co-suppression’, in which ectopic transgenes inhibited the expression of exogenous and endogenous copies of homologous genes in plants. The same phenomenon was later described in the fungus Neurospora crassa by Romano and Macino (1992), where it was described as ‘quelling’. Finally, silencing was described and molecularly characterized in Caenorhabditis elegans by the breakthrough research of Fire and Mello (Fire et al.,

 

6: Artificial Small RNA-based Strategies for Effective and Specific Gene Silencing in Plants

PDF

6

Artiicial Small RNA-based

Strategies for Effective and

Speciic Gene Silencing in Plants

Alberto Carbonell*

Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV),

Valencia, Spain

6.1

Introduction

In plants, small RNAs (sRNAs) function in diverse RNA silencing pathways to regulate development, control genome integrity and protect against viruses (Borges and

Martienssen, 2015). MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are the two main classes of plant sRNAs acting in post-transcriptional gene silencing pathways. Both associate with an ARGONAUTE (AGO) protein to target and silence highly sequence-complementary transcripts through direct AGO-mediated endonucleolytic cleavage or through their translational repression (Axtell, 2013).

MiRNAs and siRNAs differ in their biogenesis pathways as well as in the spectrum of their target transcripts. MiRNAs arise from endogenous miRNA transcripts with imperfect self-complementary foldback structures processed by DICER-LIKE1

 

7: Application of RNA Silencing in Improving Plant Traits for Industrial Use

PDF

7

Application of RNA Silencing in Improving Plant Traits for Industrial Use

Sumit Ghosh1, Mohammad Irfan2 and Asis Datta2,*

1

CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow,

India; 2National Institute of Plant Genome Research, New Delhi, India

7.1

Introduction

Besides being a major food source to the world’s ever-growing population, plants also serve as sustainable resources for petrochemicals, therapeutics, pharmaceuticals and fibres (Fesenko and Edwards, 2014). Optimization and exploitation of the huge renewable plant biomass for the efficient and cost-effective production of industrial materials are present and future challenges. Biotechnology and synthetic biology approaches are used in engineering biochemical pathways to produce as much photosynthate as possible for fuel and chemicals (Mussgnug et al., 2007;

Kalluri et al., 2014).The aim of the engineering pathway is either to over-express the gene(s) whose expression has a positive effect on product accumulation or to suppress expression of the gene(s) that negatively affect product accumulation. It is possible that both approaches may be combined to obtain superior product yield.

 

8: Increasing Nutritional Value by RNA Silencing

PDF

8

Increasing Nutritional Value by RNA Silencing

Elsa Pons1,2 and Leandro Peña1,2*

1

Instituto de Biología Molecular y Celular de Plantas (Consejo

Superior de Investigaciones Científicas Universidad Politécnica de

Valencia), Valencia, Spain; 2Fundo de Defensa da Citricultura,

Araraquara, Sao Paulo, Brazil

8.1

Introduction

The first generation of plant biotechnology products commercialized was crops focused largely on input agronomic traits whose value was usually opaque to consumers. Present and future trends are intended to continue improvement of agronomic traits; and, as value-added output characteristics such as improved nutrition and food functionality are of great interest to consumers, so biotechnology efforts go increasingly in those directions (Cressey, 2013).

Molecules in plants with dietary relevance can be grouped into four main sets: macronutrients (proteins, carbohydrates, lipids (oils), fibre), micronutrients (vitamins, minerals, functional metabolites), antinutrients (substances such as phytate that limit the bioavailability of nutrients) and allergens (intolerances and toxins); the levels of the first two would need to be increased and the latter two need to be reduced or removed. Many macro- and micronutrients are produced by plants; therefore, approaches aiming to improve the availability of these nutrients involve the adjustment of endogenous plant metabolism (Capell and Christou, 2004). Several strategies can be applied to achieve this. One of the most widely used is to reduce a metabolic bottleneck by producing more of a rate-limiting enzyme. There are other ways to increase the level of beneficial compounds such as: (i) directing biosynthetic pathways towards certain directions by repressing competitive pathways; or (ii) reducing feedback inhibition by increasing or generating a metabolic sink that would lead to a higher level of the required product (reviewed in Zhu et al., 2013). In this regard, RNAi emerged as the most suitable strategy to enhance the nutritional composition of important crop plants. Moreover, RNAi can also be used to diminish the amount of antinutrients in the plant tissues we consume by suppressing the expression of genes producing such compounds (Tang and Galili, 2004; Tang et al., 2007; Katoch and

 

9: RNA-based Control of Plant Diseases: A Case Study with Fusarium graminearum

PDF

9

RNA-based Control of Plant

Diseases: A Case Study with

Fusarium graminearum

Aline Koch and Karl-Heinz Kogel*

Justus Liebig University, Giessen, Germany

9.1

Introduction

Current strategies of plant production measures, including conventional and organic farming, are still characterized by high usage of pesticides such as copper compounds. Moreover resistance breeding, though largely successful over the years, lacks solutions where monogenic resistance traits are unspecified. In consequence, a growing population will require developing groundbreaking strategies that promote sustainable plant production. RNA interference has emerged as a powerful genetic tool for scientific research. Demonstration that agricultural pests and microbial pathogens are killed by exogenously supplied RNA targeting their essential genes has raised the possibility that plant health can be controlled by lethal RNA signals. Here we discuss recent work conducted to assess the potential of double-stranded (ds)RNA targeting essential fungal ergosterol biosynthesis genes to control the infection of barley by the necrotrophic pathogenic fungus

 

10: Targeting Nematode Genes by RNA Silencing

PDF

10

Targeting Nematode Genes by RNA Silencing

John Fosu-Nyarko*, Sadia Iqbal and Michael G.K. Jones

Murdoch University, Perth, Australia

10.1

Introduction

The free-living nematode Caenorhabditis elegans is arguably the best model for understanding RNA silencing: its anatomy and physiology allow many aspects of this natural gene regulation mechanism in eukaryotes, including the genes and the pathways involved, to be studied in detail. The successful development of this mechanism into a functional analysis tool has facilitated characterization of almost all of its genes. Following the required modifications this tool has been invaluable in assessing gene function of parasitic nematodes, and in particular in assessing the role of essential and nematode genes required for plant parasitism. Demonstration of effective silencing of plant-parasitic nematode genes after soaking infective stages in buffered dsRNA in vitro, and the ability of transgenic plant-processed small RNA triggers to effect silencing of nematodes, has opened new avenues for safe, environmentally friendly and sustainable approaches to nematode control based on RNA silencing. Current data indicate that this approach will deliver nematode resistance in crops of economic importance.

 

11: Gene Silencing Provides Efficient Protection against Plant Viruses

PDF

11

Gene Silencing Provides Efficient

Protection against Plant Viruses

Mario Tavazza,1* Alessandra Lucioli1 and Vincenza Ilardi2

1

Agenzia Nazionale per le Nuove Tecnologie, l’Energia e lo

Sviluppo Economico Sostenibile, Rome, Italy; 2Consiglio per la

Ricerca in Agricoltura e l’Analisi dell’Economia Agraria – Centro di Ricerca per la Patologia Vegetale, Rome, Italy

11.1

Introduction

One of the most significant social and economic challenges in the future will be to increase agricultural production while preserving the environment and human health

(UN-DESA, n.d.). Viral diseases can affect both the yield and the quality of crop harvest.

Although there are no exact estimates on a global scale, losses of up to 80–100% have been reported depending on the type of virus, crop, cultivar, year and region analysed

(e.g. French and Stenger, 2003). These considerations underline the importance of developing robust strategies to reduce the impact exerted by viruses on crop productivity.

 

Details

Print Book
E-Books
Slices

Format name
PDF
Encrypted
No
Sku
BPP0000222442
Isbn
9781780647685
File size
3.49 MB
Printing
Allowed
Copying
Allowed
Read aloud
Allowed
Format name
PDF
Encrypted
No
Printing
Allowed
Copying
Allowed
Read aloud
Allowed
Sku
In metadata
Isbn
In metadata
File size
In metadata