HETEROPHYLLY IN PLANTS - O.M. NEDUKHA - 2011

PREFACE

The monograph offered to the readers provides a comprehensive Overview of current achievements in The Study of heterophilly. Heterophilly has been described in numerous species of vascular plants, including both terrestrial and higher aquatic plants. In aquatic plants, some vegetative Organs grow submerged (submersed leaves, stems, roots), while other organs (aerial and floating leaves, stems, Generative organs) develop above the Water surface in the aerial environment. Despite the fundamental significance of heterophilly in plants, research into this phenomenon had long lacked sufficient development, although these issues attracted the attention of researchers several centuries ago, as highlighted, in particular, in the works of K. Goebel (Goebel, 1891; 1900; cit. in Arber, 2008), V.R. Zalensky (1918), A. Arber (1920; 2008), and others.

However, it was only in the 1960s, with the advent of spectroscopy, Electron Cell/15.html">Microscopy, and later laser-scanning confocal microscopy and molecular-Genetic Methods in laboratory practice, that more effective and informative approaches emerged for studying the functioning of photosynthetic submersed leaves. Since then, researchers have begun investigating heterophilly at the ultrastructural and molecular levels. Especially over the past two decades, a vast body of factual material has been accumulated, serving as the foundation for a new direction in botany.

Data on heterophilly have found application in taxonomic studies (Sculthorpe, 1967), investigations of global environmental changes (Goliber, 1989; Goliber, Feldman, 1989; 1990; Givnish et al., 1994), responses to low and high temperatures (Winn, 1999), variations in light intensity, and as a paradigmatic phenomenon in hydrophytes (Bradshaw, 1965). Recently, highly intriguing studies have emerged focusing on heterophilly in relation to the impacts of soil flooding or draining and the mechanisms of plant adaptation to these factors. Vascular plants growing in water have become model objects for heterophilly research.

The higher aquatic vegetation of Ukraine (true aquatic and amphiphytic) is distinguished by its uniqueness and richness, driven by natural-historical and geographical factors. According to the renowned botanist D.V. Dubyna (2006), the area of higher aquatic vegetation reaches 2.5 million ha. Aquatic vegetation plays a crucially important ecological, hydrological, ecosystem, and economic role; at the same time, it is quite vulnerable due to both steadily increasing anthropogenic pressure and the indirect impacts of ecosystem transformations within catchment areas. In this regard, preserving vegetation diversity is a pressing task, as vegetation constitutes the autotrophic block of the hydrosphere and is vital for its functioning.

This monograph highlights the main structural and Functional Characteristics of heterophilly in plants, examining the stages of their development and the potential CELLULAR AND MOLECULAR mechanisms underlying this phenomenon.

The monograph consists of two chapters. The first chapter covers the Variability of leaf blade shapes, leaf Anatomical Structure, leaf epidermal surface structure, plant phytohormonal balance, organ growth characteristics, and Photosynthesis in heterophyllous leaves. This chapter also presents the results of comparative studies on the Structural and functional Organization of leaves in Sium latifolium L., Sagittaria sagittifolia L., and Nuphar lutea (L.) Smith, which were selected by the author as model objects for studying heterophilly. The second chapter presents research findings on the effects of exogenous factors capable of inducing heterophilly, as well as advances in understanding the cellular and MOLECULAR MECHANISMS OF heterophilly expression. In light of modern knowledge regarding The Role of secondary messengers, particularly Calcium Ions, in plant environmental stress responses, we discuss our findings on the structural and functional organization of leaves in various S. latifolium forms. We also discuss the role of the amorphous form of Cellulose in apoplastic water transport across leaf Cells during successive ontogenetic stages of heterophyllous plants.

In Conclusion, the author expresses sincere gratitude to the reviewers of the monograph: Doctor of Biological Sciences Ninel Oleksandrivna Biliavska, Doctor of Biological Sciences, Prof. Svitlana Mykolaivna Zyman, and Candidate of Biological Sciences Liudmyla Ivanivna Buyun.

Research into the structural and functional organization of leaves in heterophyllous plants was conducted by the author at the Department of Cell Biology and Anatomy of the M.G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine. The author expresses sincere gratitude to Corresponding Member of the NAS of Ukraine, Doctor of Biological Sciences, Prof. Yelyzaveta Lvivna Kordium for her constant support during the experimental work; to the institute's staff (V.V. Baranenko, S.I. Zhadko, V.A. Zaslavsky, O.K. Zolotarova, D.O. Klymchyk, L.Ye. Kozeko, A.F. Popova, M.M. Fedoronchuk, H.V. Shevchenko) for participating in discussions of the experimental data; and to V.L. Ivasi and V.M. Novychenko for their technical assistance with laser scanning and electron microscopy examinations.

The Water Chestnut so, living 'mid waters still,

Spreads slender thread-like leaves at nature's will;

But hairs branch out in many a varied maze

And drink, like gills, the gas of life and days;

Yet once it reaches to the water's face,

Broad leaves it opens to embrace,

And scorched by sun, sends vapor on the breeze

And joyously drinks ether from the seas.

Erasmus Darwin. "The Temple of Nature"

(Flora of Russia)