Water And Solute Permeability Of Plant Cuticles

Transport properties of plant cuticles are important for different ?elds of modern plant sciences. Ecologists and physiologists are interested in water losses to the environment via the cuticle. Penetration of plant protecting agents and nutrients into leaves and fruits is relevant for research in agriculture and plant protection. Ecotoxicologists need to know the amounts of environmental xenobiotics which accumulate in leaves and other primary plant organs from the environment. For all of these studies suitable methods should be used, and a sound theoretical basis helps to formulate testable hypotheses and to interpret experimental data. Unnecessary experiments and experiments which yield ambiguous results can be avoided. In this monograph, we have analysed on a molecular basis the movement of molecules across plant cuticles. Based on current knowledge of chemistry and str- ture of cuticles, we have characterised the aqueous and lipophilic pathways, the nature and mechanisms of mass transport and the factors controlling the rate of movement. We have focused on structure–property relationships for penetrant tra- port, which can explain why water and solute permeabilities of cuticles differ widely among plant species. Based on this knowledge, mechanisms of adaptation to en- ronmental factors can be better understood, and rates of cuticular penetration can be optimised by plant physiologists and pesticide chemists.

The cuticle, together with its associated waxes, acts as a diffusion barrier against the uncontrolled loss of water and solutes from leaves. It forms a mechanical barrier against penetration by fungi and pests and communicates with them via chemical signa

Annual Plant Reviews, Volume 23 A much clearer picture is now emerging of the fine structure of the plant cuticle and its surface, the composition of cuticular waxes and the biosynthetic pathways leading to them. Studies assessing the impact of UV radiation on plant life have emphasized the role of the cuticle and underlying epidermis as optical filters for solar radiation. The field concerned with the diffusive transport of lipophilic organic non-electrolytes across the plant cuticle has reached a state of maturity. A new paradigm has recently been proposed for the diffusion of polar compounds and water across the cuticle. In the context of plant ecophysiology, cuticular transpiration can now be placed in the perspective of whole-leaf water relations. New and unexpected roles have been assigned to the cuticle in plant development and pollen-stigma interactions. Finally, much progress has been made in understanding the cuticle as a specific and extraordinary substrate for the interactions of the plant with microorganisms, fungi and insects. This volume details the major developments of recent years in this important interdisciplinary area. It is directed at researchers and professionals in plant biochemistry, plant physiology, plant ecology, phytopathology and environmental microbiology, in both the academic and industrial sectors.

Box 9E. 1 Continued FIGURE 2. The C–S–R triangle model (Grime 1979). The strategies at the three corners are C, competiti- winning species; S, stress-tolerating s- cies; R,ruderalspecies. Particular species can engage in any mixture of these three primary strategies, and the m- ture is described by their position within the triangle. comment briefly on some other dimensions that Grime’s (1977) triangle (Fig. 2) (see also Sects. 6. 1 are not yet so well understood. and 6. 3 of Chapter 7 on growth and allocation) is a two-dimensional scheme. A C—S axis (Com- tition-winning species to Stress-tolerating spe- Leaf Economics Spectrum cies) reflects adaptation to favorable vs. unfavorable sites for plant growth, and an R- Five traits that are coordinated across species are axis (Ruderal species) reflects adaptation to leaf mass per area (LMA), leaf life-span, leaf N disturbance. concentration, and potential photosynthesis and dark respiration on a mass basis. In the five-trait Trait-Dimensions space,79%ofallvariation worldwideliesalonga single main axis (Fig. 33 of Chapter 2A on photo- A recent trend in plant strategy thinking has synthesis; Wright et al. 2004). Species with low been trait-dimensions, that is, spectra of varia- LMA tend to have short leaf life-spans, high leaf tion with respect to measurable traits. Compared nutrient concentrations, and high potential rates of mass-based photosynthesis. These species with category schemes, such as Raunkiaer’s, trait occur at the ‘‘quick-return’’ end of the leaf e- dimensions have the merit of capturing cont- nomics spectrum.

This text presents the principles of mineral nutrition in the light of current advances. For this second edition more emphasis has been placed on root water relations and functions of micronutrients as well as external and internal factors on root growth and the root-soil interface.

This book provides a comprehensive overview of the current state of knowledge on plant-microbiome interactions and associations. It covers all major mechanistic approaches used to investigate microbes’ impacts on plant growth promotion, disease control and health. The industrial manufacture of nitrogen currently accounts for roughly 2% of the world’s total energy consumption. Microbial products are expected to reduce the need for costly fertilizers, as well as chemical pesticides and fungicides. While beneficial microorganisms are increasingly being used in agriculture, abiotic and biotic stresses such as heat, drought, cold, and salt can quickly kill or render them useless in the field. However, discovering new and better treatments is a lengthy process due to the considerable microbial diversity found in soils. Researchers have now proposed using biotechnological approaches to accelerate the process of microbial technology development. The fact that plant-associated microbes stimulate plant growth and development is well known, as the examples of rhizobia and mycorrhizal fungi show. The mechanisms by which these microorganisms maintain plant growth include the production of phytohormones, fixation of nitrogen, and the mobilization of phosphorus and minerals. The plant microbiome is also involved in pathogen suppression, and especially the root microbiome acts as a protective shield against soil-borne pathogens. A special feature of this book is its multidisciplinary approach, spanning from plant microbiology/biocontrol, fungal and bacterial endophytes, plant physiology, to biochemistry, proteomics and genomics. It is ideally suited for researchers and student of agri-biotechnology, soil biology and fungal biology.

This volume will be the only existing single-authored book offering a science-based breeder’s manual directed at breeding for water-limited environments. Plant breeding is characterized by the need to integrate information from diverse disciplines towards the development and delivery of a product defines as a new cultivar. Conventional breeding draws information from disciplines such as genetics, plant physiology, plant pathology, entomology, food technology and statistics. Plant breeding for water-limited environments and the development of drought resistant crop cultivars is considered as one of the more difficult areas in plant breeding while at the same time it is becoming a very pressing issue. This volume is unique and timely in that it develops realistic solutions and protocols towards the breeding of drought resistant cultivars by integrating knowledge from environmental science, plant physiology, genetics and molecular biology.