New and Future Developments in Microbial Biotechnology and Bioengineering

Crop Improvement through Microbial Biotechnology

Ram Prasad, Sarvajeet Singh Gill, Narendra Tuteja

• Publisher: Elsevier
• Year: 2018
• ISBN:
  9780444639882
• Topic: Technology & Engineering
• Subtopic: Chemical & Biochemical Engineering
• Index: Technology & Engineering

Crop Improvement through Microbial Biotechnology explains how certain techniques can be used to manipulate plant growth and development, focusing on the cross-kingdom transfer of genes to incorporate novel phenotypes in plants, including the utilization of microbes at every step, from cloning and characterization, to the production of a genetically engineered plant. This book covers microbial biotechnology in sustainable agriculture, aiming to improve crop productivity under stress conditions. It includes sections on genes encoding avirulence factors of bacteria and fungi, viral coat proteins of plant viruses, chitinase from fungi, virulence factors from nematodes and mycoplasma, insecticidal toxins from Bacillus thuringiensis, and herbicide tolerance enzymes from bacteria.

• Introduces the principles of microbial biotechnology and its application in crop improvement
• Lists various new developments in enhancing plant productivity and efficiency
• Explains the mechanisms of plant/microbial interactions and the beneficial use of these interactions in crop improvement
• Explores various bacteria classes and their beneficial effects in plant growth and efficiency

Chapter 1

The Use of Microorganisms for Gene Transfer and Crop Improvement

Mehmet C. Baloglu*; Musa Kavas^†; Songül Gürel^‡; Ekrem Gürel^{§ *} Kastamonu University, Kastamonu, Turkey
^† Ondokuz Mayıs University, Samsun, Turkey
^‡ Sugar Institute, Ankara, Turkey
^§ Abant Izzet Baysal University, Bolu, Turkey

Abstract

Microorganisms have been extensively used in several fields of biomass production in food and medicinal industries and in genetic transformation studies. Steady increase in world population has forced the scientists to meet the increasing demand in food all over the globe. Crop breeding through conventional methods has historically contributed a large extent in improving the yield and quality parameters of almost all edible and industrial crops. Also, a significant degree of credit should be attributed to the modern technologies of biotechnology including genetic transformation technologies via several microorganisms. In this chapter, gene transfer technologies of crop species via both Agrobacterium tumefaciens and A. rhizogenes were reviewed in detail. Also, non-Agrobacterium-based technologies were briefly touched. As to the main focuses of the transformation efforts in plants, the improvements of these traits were studied: herbicide resistance, insect resistance, improved nutritional values, abiotic stress tolerance, and molecular farming/pharming. Finally, virus-induced transient gene expression studies in plants are shortly addressed.

Keywords

Microorganisms; Gene transfer; Crop improvement; Agrobacterium; Resistance; Nutritional improvement; Abiotic stress tolerance

1 Agrobacterium-Based Technologies

1.1 Gene Transfer Through Agrobacterium Tumefaciens

Steady increase in world population is forcing the scientists to increase agriculture production. Earlier crop improvement techniques based on hybridization of genotypes have had different characteristics. However, crop improvement through conventional breeding methods requires a wide gene pool in genetically close plant species. By discovery of recombinant DNA technology, genetic engineering has become the most widely used tool in crop improvement. One of the most important developments in plant biotechnology is the ability of transferring foreign genes into plant genome. The gene transfers between crops and other unrelated organisms, which have potential candidate genes, lead to the production of improved varieties in terms of yield and resistance to disease, pest, and herbicides. Many different genetic transformation techniques were developed to obtain transgenic plants over the last three decades. Among various gene delivery techniques, Agrobacterium-mediated genetic transformation and particle bombardment are the most widely used for the genetic engineering of plants. Low copy number transgenesis and the production of high-quality transgenic plants are the most important advantages of Agrobacterium-mediated gene transfer when compared to the particle bombardment or biolistic (Dai et al., 2001). The first genetically modified plant was produced in 1982 with A. tumefaciens by using tobacco leaf tissue (Fraley et al., 1983). Up to now, gene transfer with disarmed (nontumorigenic) Agrobacterium strains has been achieved by using more than 120 plant species such as maize, wheat, soybean, cotton, tobacco, and rice (Abhishek et al., 2016). A. tumefaciens, a member of Rhizobiaceae family, has been used for genetic transformation studies in plants. This ubiquitous gram-negative soil bacterium has an ability to transfer its segment of plasmid (Ti-Ri plasmid) surrounded by repeated nucleotides into plant genome naturally. The typical Ti plasmid, with a crucial role in crown gall disease, is about 200 kb. Naturally grown Agrobacterium cells carry two types of gene on T-DNA region. The first one known as oncogenic genes includes auxin and cytokinin genes. The others are responsible for opine and agropine synthesis in infected plant tissues (Gustavo et al., 1998). The proteins coded by vir (virulence) genes carried out the transfer of T-DNA region into the plant cells. Phenolic substances released from wounded plant tissues induce the activation of vir genes located in tumor-inducing (Ti) plasmid of A. tumefaciens. There are about 30 genes in A. tumefaciens vir regulon, and about 20 of them are required for tumor formation in plant tissues (Gelvin, 2003). This regulon consists of at least six operon (VirA, VirB, VirC, VirD, VirG, and VirE) required for single-stranded T-DNA generation and transfer into the host plant cell genome (Fig. 1) (Gustavo et al., 1998; Zupan and Zambryski, 1997).

Fig. 1 Single-stranded T-DNA generation and transfer into the host plant cell genome.

The improvement of plants through the gene transfer mainly relies on the tissue-culture response of genotypes or species. In order to generate transgenic plants, suitable transformation methods and a robust regeneration protocol are required. By this context, some of the species and explants may not be suitable for Agrobacterium-mediated gene transfer. Especially, monocotyledon plant species are recalcitrant to Agrobacterium-mediated transformation. These groups of plants are not naturally infected by A. tumefaciens due to the lack of phenolic substances required for induction of vir genes. By using artificial phenolic substances and hypervirulent strain, monocot plants such as cereal can be transformed by A. tumefaciens. Another group of plants also cannot be genetically engineered because of their low regeneration potential. As previously mentioned, the production of transgenic plants requires tissue- culture steps. Recently, tissue-culture-independent methods have been demonstrated to work in a limited number of plant species. One of the most promising tissue-culture-independent methods is called floral-dip transformation. Arabidopsis thaliana plant can efficiently be transformed by using this technique (Feldmann and Marks, 1987). This technique, which removes the need for tissue culture, has been successfully applied to other plants such as soybean, radish, tomato, brinjal, and snake gourd (Hu and Wang, 1999; Curtis and Nam, 2001; Park et al., 2005; Yasmeen et al., 2009; Subramanyam et al., 2015).

1.2 Gene Transfer Through Agrobacterium Rhizogenes

The other important phytopathogens have gene transfer ability, and the cause to hairy root disease is A. rhizogenes (Gelvin, 2009). The A. rhizogenes-mediated transformation characterized by hairy root formation takes place by transferring T-DNAs from the Ri plasmid into plant cell (Tepf...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Chapter 1: The Use of Microorganisms for Gene Transfer and Crop Improvement
• Chapter 2: Actinomycetes as Potential Plant Growth-Promoting Microbial Communities
• Chapter 3: Microbial Genes in Crop Improvement
• Chapter 4: Microbial Transformations Implicit With Soil and Crop Productivity in Rice System
• Chapter 5: Application of Microbial Biotechnology in Food Processing
• Chapter 6: Innate Immunity Engaged or Disengaged in Plant-Microbe Interactions
• Chapter 7: Novel Strategies for Engineering Resistance to Plant Viral Diseases
• Chapter 8: Molecular Characterization of Sugarcane Viruses and Their Diagnostics
• Chapter 9: Cyanobacterial Biodiversity and Biotechnology: A Promising Approach for Crop Improvement
• Chapter 10: Pseudomonas fluorescens: A Plant-Growth-Promoting Rhizobacterium (PGPR) With Potential Role in Biocontrol of Pests of Crops
• Chapter 11: Crop Improvement Through Microbial Technology: A Step Toward Sustainable Agriculture
• Chapter 12: Microbial Technologies for Sustainable Crop Production
• Chapter 13: Trichoderma: Its Multifarious Utility in Crop Improvement
• Chapter 14: Microbe-Mediated Enhancement of Nitrogen and Phosphorus Content for Crop Improvement
• Chapter 15: Microbiome in Crops: Diversity, Distribution, and Potential Role in Crop Improvement
• Chapter 16: Plant Growth-Promoting Rhizobacteria (PGPR): Perspective in Agriculture Under Biotic and Abiotic Stress
• Chapter 17: Rhizosphere Metabolite Profiling: An Opportunity to Understand Plant-Microbe Interactions for Crop Improvement
• Chapter 18: Phosphate-Solubilizing Pseudomonads for Improving Crop Plant Nutrition and Agricultural Productivity
• Chapter 19: Targeted Genome Editing for Crop Improvement in Post Genome-Sequencing Era
• Chapter 20: Endophytic Microorganisms: Their Role in Plant Growth and Crop Improvement
• Chapter 21: Microbes in Crop Improvement: Future Challenges and Perspective
• Chapter 22: Plant-Microbe Interaction and Genome Sequencing: An Evolutionary Insight
• Chapter 23: Crop Breeding Using CRISPR/Cas9
• Chapter 24: Bioprospecting PGPR Microflora by Novel Immunobased Techniques
• Index