Several people have already responded to confirm that Moore et al.'s text
is basically correct on the question of photorespiration in CAM plants.
The text does underestimate the agricultural importance of CAM plants by
saying only pineapple and an agave are agriculturally significant.
Kalanchoe blossfeldiana is the top greenhouse potted plant in Denmark and
important enough in the U.S. to merit a separate chapter in Roy Larson's
text, Introduction to Floriculture. (1992, Academic Press). Many CAM
plants are important as houseplants, such as Hoya carnosa, cacti, and
several other Kalanchoe spp. Several CAM plants, like cacti, are important
in arid landscaping, and large cultivated specimens are so expensive that
wild specimens are often stolen from nature. Botany textbooks usually
overlook or underemphasize that horticulture is a part of agriculture and
botany.
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David R. Hershey
Snail mail: 6700 Belcrest Road #112, Hyattsville, MD 20782-1340
Adjunct Professor, Biology/Horticulture Department
Prince George's Community College, Largo, MD 20772-2199
Email: dh321 at pgstumail.pg.cc.md.us
*******************************************************************
On 20 Nov 1996 Peggy.Pollak at NAU.EDU wrote:
> Please help, and in a hurry! Moore et al. state that CAM plants do
> not exhibit photorespiration. I don't buy it. If carbon dioxide
> is secondarily fixed in the mesophyll chloroplasts by rubisco during
> the day, and these are normal chloroplasts containing thylakoids,
> there should be plenty of oxygen ergo photorespiration. I am at a
> loss to explain the statement in Moore et al. to my class of budding
> college botanists. Please respond to the bio.net so that my students
> can read the responses, too. Thanks.
>> Peggy Pollak
>
