15 thursday december 6 12 symbiosis between xylella

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Unformatted text preview: Symbiosis between Xylella and sharpshooters Organism Organism Class of symbiosis A B recent study show that there is possibility that xylella actually help sharpshooter get its nutrient Mutualism + + Commensalism + 0 Parasitism + - Symbiosis between Xylella and sharpshooter? 16 Thursday, December 6, 12 Lecture 36 Outline • Grapes and Their Problems • How Pierce’s Disease Gets Around • Phloem, Aphids and Their Symbionts • Xylem, Sharpshooters and Their Symbionts 17 Thursday, December 6, 12 Xylem and Phloem Xylem sap: water and minerals mostly from roots to rest of plant. ^nutrient poor Phloem sap: products of photosynthesis such as sugars to sites of storage or use. know a lot more about this and also there a lot more organisms that feed on the phloem instead of the xylem From Lodish et al. 2000 18 Thursday, December 6, 12 35.12 Aphids Live off Phloem Sap aphids is similar to the sharpshotter but feeds on the phloem aphids is a successful organism 19 Thursday, December 6, 12 Conundrum • Phloem sap is filled with sugar(s) and a variety of other compounds • But low in most of the “essential” amino acids that animals cannot synthesize over evolutionary time, plants removed some of the things from phloem that animals need. [N-rich amino acid also essential amino acids] aphids is an obligate phloem feeder (don't eat anything else). how do aphids (and other organisms) can survive from just eating plants that have low amount of essential A.A. 20 Thursday, December 6, 12 Aphids are very successful (> 4000 species, everywhere you look) 22 Thursday, December 6, 12 Plant response to sap feeders • Possible solutions to low aa in phloem Eat other things Evolve metabolic pathways to synthesize missing nutrients animals is not good at generating new metabolic pathway Find some poor sap to make the stuff for you symbiosis 23 Thursday, December 6, 12 inside certain cells associated with their gut... there are microorganism in t...
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This document was uploaded on 04/13/2013.

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