Silicon and Plant Diseases

ISBN-13: 9783319352626 / Angielski / Miękka / 2016 / 148 str.

Fabricio a. Rodrigues; Lawrence E. Datnoff

Spis treści

1. History of Silicon and Plant Disease
Abstract
Introduction
Discovery of silicon affecting plant diseases in monocots
Discovery of silicon affecting plant diseases in dicots
Conclusions
References

2. Silicon in Soils and Plants
Abstract
Introduction
Silicon in soils
Silicon cycle in soil
Interaction of silicon with other plant nutrients in the soil
Silicon in plant
Silicon sources
Measuring silicon concentration
Conclusions
References

3. Silicon Control of Soil-borne and Seed-borne Diseases
Abstract
Introduction
Diseases caused by soil-borne pathogens
Diseases caused by seed-borne pathogens
Conclusions
References

4. Silicon Control of Foliar Diseasesin Monocots and Dicots
Abstract
Introduction
Fungal diseases
Bacterial diseases

Viral diseases
Interaction of silicon and fungicides
The efficiency in applying silicon via the foliage versus the root in controlling plant disease

Conclusions
References

5. Silicon Potentiates Host Defense Mechanisms Against Infection by Plant Pathogens
Abstract
Introduction
The physical barrier hypothesis
Biochemical and molecular aspects of silicon-mediated host resistance to pathogens
Silicon-mediated host resistance to pathogens through changes in the primary metabolism
Conclusions
References

6. Highlights and Prospects for Using Silicon in the Future
Abstract
Introduction
What information do we still need to improve the deployment of silicon for managing plant diseases?
Why is silicon still not used routinely for managing plant diseases under greenhouse and field conditions?
Conclusions
References

Blurb

One of the most notable plant effects of silicon is the reduction in the intensities of a number of plant diseases caused by biotrophic, hemibiotrophic, and necrotrophic pathogens. This reduction in symptom expression is due to the element’s effect on a number of components of host plant resistance that includes the incubation period, latent period, lesion size, lesion number and inoculum production. Silicon also has been demonstrated to decrease certain diseases to the same level of intensity as a fungicide while augmenting susceptible cultivars to a level of resistance equivalent to complete genetic resistance. The mechanical barrier hypothesis, resulting from silicon polymerization below the cuticle and in the cell walls, was first proposed to explain how this element reduced plant disease development. However, new insights have revealed that plants supplied with silicon had the phenylpropanoid pathway greatly potentiated (increase in the concentrations of total soluble phenolics and lignin), the activities of defense enzymes such as chitinases and β-1,3-glucanases kept higher during the pathogen´s infection process as well as the transcription of many genes related to plant defense occurred in a much faster and stronger manner. Even an improvement was noted in the antioxidant metabolism that contributed to the reduction in the cytotoxic effect of the reactive oxygen species that cause lipid peroxidation in the cell membrane. At the physiological level, the values of the leaf gas exchange parameters are kept higher upon pathogen infection and positively affected photosynthesis.

A number of facts are now known about the role of silicon in reducing plant diseases that include as silicon concentration (insoluble or soluble) increases in plant tissue, plant disease suppression will be dramatically improved; the silicon supply to the plant must be continuous or disease suppressive effects are reduced or non-existent; and silicon, only when root applied, will change the response of plants to infection by the pathogen at both the physiological and molecular level. As researchers and growers become more aware of silicon and its potential, this often overlooked “quasi-essential” element will be recognized as a viable means of enhancing crop health and performance.