Question for those with scientific knowledge | International Carnivorous Plant Society

gregallan
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Posts: 83

Question for those with scientific knowledge May 3, 2012 8:52:00 GMT

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Post by gregallan on May 3, 2012 8:52:00 GMT

I was wondering whether anyone of a scientific bent could possibly provide an explanation for this small passage:

"During the course of the present studies, we have also examined the acid proteinase activities of the digestive fluids of some other carnivorous plants. So far, the digestive fluids of Drosophyllum lusitanicum and Byblis liniflora showed high activity toward both hemoglobin and oxidised insulin B chain, whereas that of Sarracenia purpurea failed to give any activity toward hemoglobin."

It is on pp80-81of this article: Takahashi, Kenji and Koji Matsumoto and Wataru Nishii and Miho Muramatsu and Keiko Kubota and Chiaki Shibata and Senareth B.P. Athauda (2009) Comparative studies on the acid proteinase activities in the digestive fluids of Nepenthes, Cephalotus, Dionaea, and Drosera. Carniv. Pl. Newslett. 38(3):75-82- available here: www.carnivorousplants.org/cpn/articles/CPNv38n3p75_82.pdf

I am particularly interested in the implications for B liniflora, as I was under the impression that this plant has yet to be proven to produce proteases.

Any enlightenment will be much appreciated.

Greg

voidgenesis
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Posts: 9

Question for those with scientific knowledge Oct 19, 2012 4:20:46 GMT

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Post by voidgenesis on Oct 19, 2012 4:20:46 GMT

Your interpretation appears correct.
The experimenters would have taken some pure proteins (hemoglobin and insulin) and exposed them to slightly acidic conditions with or without the excretions from Drosophyllum present. They then would have analysed the protein to see if it was still intact or had been broken down into smaller elements. So this study then shows that there is some factor in Drosophyllum and Byblis secretions that cause proteins to be digested (most probably a protease enzyme like other carnivorous plants).
(From a biochem PhD)

gregallan
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Posts: 83

Question for those with scientific knowledge Nov 26, 2012 19:14:55 GMT

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Post by gregallan on Nov 26, 2012 19:14:55 GMT

Hi Voidgenesis,

I have only just noticed this reply. Thank you very much- this is very interesting. I am surprised that this finding was not published with more fanfare. As far as I am aware, this is the first published evidence of protein digestion in B liniflora.

Thanks,

Greg

adamcross
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Question for those with scientific knowledge Nov 27, 2012 3:34:53 GMT

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Post by adamcross on Nov 27, 2012 3:34:53 GMT

Hi Greg,

Carnivory in B. liniflora was previously determined by Plachno et al. 2006 (along with tests on 46 other species), through analysis of phosphatase activity by enzyme labelled fluorescence.

You can find the article here: www2.butbn.cas.cz/adamec/Plachno3.pdf

Adam

gregallan
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Posts: 83

Question for those with scientific knowledge Nov 27, 2012 23:31:35 GMT

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Post by gregallan on Nov 27, 2012 23:31:35 GMT

Hi Adam,

Thanks for your reply. I am aware of the 2006 article- there is a very interesting discussion of it here: www.cpukforum.com/forum/index.php?showtopic=16662. I think that the general understanding is that most CPs produce proteases as well as phosphatases. There were crude tests conducted by Bruce at the beginning of the 20th century which indicated that B gigantea is able to digest proteins, and Hartmeyer recently demonstrated that B filifolia produces proteases. He was unable to find evidence of proteases in B liniflora, however, and the production thereof had not previously been proven in B liniflora. This is why I think that these results are especially significant.

Furthermore, as far as I am aware, no research has ever been published that conclusively demonstrates nutrient uptake by any species of Byblis (i.e. using tagged isotopes). I think that the evidence does strongly support the inclusion of Byblis as carnivores, but it has to be conceded that the genus has been little studied in comparison to virtually all other genera of CPs.

Greg

Last Edit: Nov 27, 2012 23:32:45 GMT by gregallan