US EPA

474368 

Journal Article 

Anatomical features and ultrastructure of Deschampsia antarctica (Poaceae) leaves from different growing habitats 

Gielwanowska, I; Szczuka, E; Bednara, J; Gorecki, R 

2005 

Yes 

Annals of Botany
ISSN: 0305-7364
EISSN: 1095-8290 

96 

6 

1109-1119 

English 

16157630 

10.1093/aob/mci262 

WOS:000232746300014 

Background and Aims The leaf anatomy and ultrastructure of Deschampsia antarctica (Poaceae) plants growing in three different habitats (a dry site in the Antarctic tundra, a wet site in a zone exposed to sea spray and a greenhouse) were investigated. The ultrastructure of the leaves of D. antarctica has not been studied before. Methods Semi-thin sections of the D. antarctica leaves were stained with toluidine blue and viewed using a light microscope. Ultra-thin sections stained with uranyl acetate and lead citrate were examined using a transmission electron microscope. Key Results Plants growing in the Antarctic tundra and in a greenhouse had stronger xerophytic features than those growing at the seashore. The stress response of D. antarctica plants growing in the wet environment, exposed to high salinity and flooding, included: irregular mesophyll cells, large intercellular spaces in the parenchymatic layer, bulliform epidermal cells and vascular bundles surrounded with deformed outer and inner bundle sheaths of leaves. The highest number of sclerenchymatic fibres is characteristic of the leaves of plants growing in a greenhouse, whereas the smallest was of plants growing in a wet habitat. Stress conditions can disturb the formation of sclerenchymatic fibres. In plants growing in the Maritime Antarctic the chloroplasts of the mesophyll cells of leaves are of an irregular shape, with pockets or invaginations inside the organelles and outgrowths. Both of them make the surfaces of chloroplasts larger, and result in an increase in the amount of substances exchanged between the chloroplasts and cytoplasm or the other organelles. The leaf mesophyll cells of D. antarctica plants growing in Antarctica contain atypical structures including numerous vesicles of different sizes and concentrically arranged membranes. Conclusions The anatomical and ultrastructural features of the leaf and their changes under stress conditions are considered in relation to the adaptations of D. antarctica to the climate conditions in the Maritime Antarctic. 

Deschampsia antarctica; anatomical features; mesophyll cells; ultrastructure; stress condition; Poaceae; Antarctica; phenotypic; plasticity; phenotypic response; uv-b radiation; vascular plants; colobanthus-quitensis; abscisic-acid; growth; reproduction; metabolism; field