Plant Physiology - Lecture Notes - O. M. Tarnopilska 2019

1. Fundamentals of Plant Physiology
1.4 Methods of Plant Physiology

Plant physiology methodology is based on METABOLISM/2.html">THE CONCEPT OF the plant Organism as a complex, self-regulating system characterized by a hierarchy of structural levels, ranging from the subcellular (macromolecular) level to the whole plant.

The challenges and tasks of plant physiology are so complex that solving them requires a comprehensive range of advanced Physicochemical Methods, alongside diverse experimental and theoretical approaches. This is precisely why the discipline belongs to the core fundamental sciences.

Methods of plant physiology include: analytical, synthetic, historical, and experimental.

To understand the regularities of plant life Functions, it is first necessary to analyze individual manifestations of its activity and examine in detail the Physical and Chemical phenomena underlying them. These can be uncovered using the analytical method. Having investigated the individual components, the physiologist must then reconstruct the picture of the plant organism's activity as an integrated whole. To achieve this, the synthetic method must also be applied, taking into account the specific patterns of life processes in various plant species and varieties, as well as their dependence on environmental conditions.

The Structure/175.html">Implementation of the synthetic method has driven The Development of the physiology of individual crops—applied physiology. However, for experimental or logical synthesis, a physiologist must also understand the evolutionary history of organisms. Therefore, this approach must be complemented by the historical method.

The advancement of plant physiology, like any other science, relies not only on novel ideas but also on new methodologies. Historically, much of our knowledge in plant biology was acquired using methods that yielded only discrete information about metabolic activity. However, physiological functions and biochemical metabolic reactions predominantly occur in a non-linear, oscillatory regime. Consequently, elucidating their mechanisms requires modern techniques—such as Infrared Spectroscopy, radioactive and stable isotopes, NMR and positron emission tomography, and fluorescent probes—which allow researchers to record the spatiotemporal parameters of metabolic processes without disrupting the integrity of the organism. Recently, new insights into plant mechanisms have accumulated rapidly due to the integration of modern molecular biology, Introduction/32.html">Genetic Engineering, and Cell culture techniques with classical physiological methods. These approaches enable the real-time study of metabolic cycle dynamics in the intact plant cell.

Across various fields of plant biology, cutting-edge molecular-biological methods are being widely adopted to study the expression of numerous individual genes and the physiology of genetically modified organisms. Technologies have been developed to produce Transgenic Plants with targeted traits—such as «golden rice», which synthesizes and accumulates provitamin A. The Emergence of this new Class of genetically modified organisms has significantly expanded the methodological scope for fundamental research involving transgenic plants. Consequently, substantial attention is now focused on the physiology of transgenic plants, their production, and the Practical Application of genetically modified forms. Transgenic plants already occupy tens of millions of hectares, replacing their conventional counterparts, which necessitates a thorough investigation into all metabolic features of such organisms.

In addition to genetic engineering, cell technologies offer vast opportunities for generating diverse new plant forms. Methods have already been established that allow researchers to control The properties of a unique, experimentally created biological system—a population of plant somatic Cells in vitro (for instance, by adding growth regulators to the nutrient medium). The in vitro system provides a powerful tool for investigating the CELLULAR AND MOLECULAR basis of morphogenesis. Research into the Genetic control of morphogenesis in vitro is of paramount importance for the development and refinement of various plant biotechnologies. Furthermore, in vitro biological systems hold great promise for preserving the Gene pool of valuable bioresources, notably through cryobanks designed for the conservation of prized cultivated and wild species.