High altitude plants

Keiller DR, Holmes MG (2001) Effects of long-term exposure to elevated UV-B radiation on the photosynthetic performance of five broad-leaved tree species. Photosynth Res 67 229-240 Kogami H, Hanba YT, Kibe T, Terashima I, Masuzawa T (2001) C02 transfer conductance, leaf structure and carbon isotope composition of Polygonum cuspidatum leaves from low and high altitudes. Plant Cell Environ 24 529-538... 

HIGH ALTITUDE PLANTS, CHEMISTRY OF ACCLIMATION AND ADAPTATION... 

The first mechanism comprises a widespread form of defense collectively known as phototoxieity (Fig. 13), which is aimed at plant predators. After ingestion of these phototoxins and subsequent exposure to sunlight the free-radicals thus formed damage internal tissues (e.g. Downum, 1992). In high altitude plants, this process not only would harm herbivores which could otherwise protect themselves by opaque cuticles, but also may damage the plant itself by oxidative stress (Fig 14). 

TD-accumulation in UV-B adapted plants leads to the notion that they might suffer from the free-radical forming reactions typical of oxidative stress, regardless of the attenuation by chemical UV-B filters. It would not be surprising, therefore, that these high altitude plants were successful producers of efficient antioxidants. It was already mentioned that the... 

Gupta, O.P., Srivastava, T.N., Gupta, S.C. and Badola, D.P. (1981). Ethanobotanical screening of high altitude plants of Ladakh- II. Bull. Medico-ethanobotany Research, 2 67-88. 

Speculate on possible advantages for high altitude plants to be shorter than lower altitude plants. Of these, which do you think would be the most important, and why ... 

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