A plant's arsenal of crystalline darts and sand
August 6, 2009
A string of biforine-like cells associated with the anther of Dieffenbachia seguine (Jacq.) Schott. (Araceae). These cells contain bundles of thin pointed crystals of calcium oxalate, which they may be able to expel forcibly. It is plausible that these crystals protect the pollen from herbivory. Dieffenbachia seguine produces a diverse variety of crystal-containing cells in every organ, suggesting that crystals play a variety of roles in the plant, but the roles remain unknown. Anthers were hand-sectioned, cleared, and photographed under polarization microscopy. The image is approximately 1300x magnified. Credit: Courtesy of Gary G. Cote, Radford University, Radford, Va.
Pet owners have heard the warnings to keep certain poisonous houseplants away from their pets, such as Dieffenbachia (dumbcane), Philodendron, peace lily, and pothos. For houseplants like these and others, the problem may not just be a poison, but the presence of tiny crystals throughout the plant.
A discussion of plants may not bring to mind crystals; however, crystals are found in hundreds of plant families. Despite this, their purpose is not well-understood. Hypotheses include acting as a deterrent to herbivory, serving as a long-term storage depot for calcium, or providing extra support to various plant tissues.
To help elucidate the role of crystals in plants and determine whether this role may actually be to prevent animals from munching on the plant, Dr. Gary Coté studied the variety and locations of crystals found in the houseplant Dieffenbachia seguine. His findings have just been published in the July 2009 issue of the American Journal of Botany.
Three common types of crystals are found in plants: druses (spherical crystal aggregates), raphides (long pointed needles found in bundles), and prisms. Coté found all three of these in Dieffenbachia. He discovered that each type of tissue within the plant, as well as different portions of the same organ in some instances, had their own specific crystals. And, despite the variety of crystal structures found throughout the plant, all crystals were found to contain calcium oxalate, the same substance comprising kidney stones.
Dr. Cote's findings suggest that the most common role for crystals may be to act as a deterrent to herbivory, with different types of crystals performing different roles in protecting the plant. The druses, found throughout the plant, would abrade the mouth of any animal unfortunate enough to take a bite of the plant, creating a sensation of chewing sand. The needle-like raphides are most commonly found in leaves, the part of the plant most likely to be eaten. The act of chewing the leaves can result in the forcible expulsion of these raphides from the plant tissue, turning the crystals into microscopic darts. Box-like bundles of raphides are found in the stem and other areas that would benefit from the extra support they provide. Prismatic crystals are only found mixed with pollen, and this suggests they may play a role in pollen dispersal or germination.
So when pet owners are looking for a location for a new houseplant, they should make sure their pet can't snack on it if it's a plant with calcium oxalate raphides. Dogs may not be so happy if they end up with a mouthful of grit or microscopic darts, although those crystals may very well be doing their job.
More information: http://www.amjbot. … ll/96/6/1075
Source: American Journal of Botany
-
Solving the mystery of the metallic sheen of fish
Jan 14, 2008 |
not rated yet |
0
-
Colluding with colloids: Scientists make liquid crystal discovery
Dec 14, 2006 |
not rated yet |
0
-
First-class protein crystals thanks to weightlessness on earth
Apr 23, 2008 |
not rated yet |
0
-
The Unusual Origin of Peacock Brown
Jun 28, 2005 |
not rated yet |
0
-
Physicist's Snowflake Images Get Stuck
Oct 15, 2006 |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (4) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (2) |
0
-
Factors affecting beet root cell membrane
18 hours ago
-
Stem cell question.
Feb 10, 2012
-
Protease cleavage
Feb 10, 2012
-
Pertubance in a model
Feb 10, 2012
-
Cancer drugs and Alzheimer's, Oh my!
Feb 09, 2012
-
Squishing cells
Feb 09, 2012
- More from Physics Forums - Biology
More news stories
Integrated pest management recommendations for the southern pine beetle
The southern pine beetle, Dendroctonus frontalis Zimmermann, is a chronic insect pest within pine forests in the southeastern United States. Under favorable environmental and host conditions, it is an agg ...
10 minutes ago |
not rated yet |
0
A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...
14 hours ago |
4.5 / 5 (22) |
0
|
Researchers find extensive RNA editing in human transcriptome
In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...
14 hours ago |
5 / 5 (4) |
0
|
The proteins ensuring genome protection
Researchers from the University of Geneva (UNIGE), Switzerland, have discovered the crucial role of two proteins in developing a cell 'anti-enzyme shield'. This protection system, which operates at the level of molecular ...
14 hours ago |
5 / 5 (3) |
0
|
Entire genome of extinct human decoded from fossil
(PhysOrg.com) -- In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The ...
Feb 07, 2012 |
4.7 / 5 (60) |
51
|
Japan's Fukushima reactor may be reheating: operator
Temperature readings at one of the crippled Fukushima nuclear reactors have risen above Japan's stringent new safety standard but there was no immediate danger, its operator said Sunday.
Botox developer rues missing out on billions
Botox developer Alan Scott says he rues the day he handed over rights to the best-selling wrinkle-smoothing drug to a US company for just $4.5 million, saying he might have become a billionaire.
Australian women reject 'I love u' texts
Australian women may have embraced the digital era, but they prefer a face-to-face declaration of affection to an "I love u" text and find men addicted to their mobile phones a major turnoff.
Many lung cancer patients get radiation therapy that may not prolong their lives
A new study has found that many older lung cancer patients get treatments that may not help them live longer. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the findings suggest that p ...
Young adults allowed to stay on parents' health insurance have improved access to care
Researchers from Mount Sinai School of Medicine have found that laws permitting children to stay on their parents' health insurance through age 26 result in improved access to health care compared to states without those ...
Cancer rate 4 times higher in children with juvenile arthritis
New research reports that incident malignancy among children with juvenile idiopathic arthritis (JIA) is four times higher than in those without the disease. Findings now available in Arthritis & Rheumatism, a journal publis ...
Aug 06, 2009
Rank: not rated yet
Aug 07, 2009
Rank: not rated yet
http://www.amjbot...6/7/1245