Free amino acids in the phloem sap from oats and barley resistant to Rhopalosiphum padi

Weibull, Jens

doi:10.1016/0031-9422(88)80098-0

Cited by 57 publications

(43 citation statements)

References 23 publications

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“…These values are similar to those observed from other aphids (e.g., Febvay et al, 1988). The amino acid profiles of the proteins plus peptides of the two aphid species were Weibull et al (1988). 3 Kajimura, et al (1995).…”

Section: Resultssupporting

confidence: 72%

How nutritionally imbalanced is phloem sap for aphids?

Sandström

Moran

1999

Entomologia Exp Applicata

141

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Aphids harbour intracellular symbionts (Buchnera) that provide their host with amino acids present in low amounts in their diet, phloem sap. To find out the extent to which aphids depend on their symbionts for synthesis of individual essential amino acids, we have evaluated how well phloem sap amino acid composition matches the aphids' needs. Amino acid compositions of the ingested phloem sap were compared to amino acids in aphid body proteins and also to available information about optimal diet composition for other plant feeding insects. Phloem sap data from severed stylets of two aphid species, Rhopalosiphum padi (L.) (Homoptera: Aphididae) feeding on wheat, and Uroleucon sonchi (L.) (Homoptera: Aphididae) feeding on Sonchus oleraceus (L.), together with published information on phloem sap compositions from other plant species were used.Phloem sap has in general only around 20% essential amino acids, with a range from 15-48%. Aphid body proteins and optimal diets for two other plant feeding insects have around 50%. The phloem sap of early flowering S. oleraceus ingested by U. sonchi contained 48%, which seems to be exceptional. Aphids feeding on different plants appear to be very differently dependent on their symbionts for their overall essential amino acid synthesis, due to the large variation in proportion of essential amino acids in phloem sap from different plants.The profile of the essential amino acids in phloem sap from different plant species corresponds rather well to profiles of both aphid body proteins and optimal diets determined for plant feeding insects. However, methionine and leucine in phloem sap are in general low in these comparisons, suggesting a higher dependence on the symbiont for synthesis of these amino acids. Concentrations of several essential amino acids in phloem from different plant species seem to vary together, suggesting that levels of symbiont provisioning of different amino acids are adjusted in parallel.

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Section: Resultssupporting

confidence: 72%

How nutritionally imbalanced is phloem sap for aphids?

Sandström

Moran

1999

Entomologia Exp Applicata

141

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“…The total molarity of the amino acids varied over a wide range, from a low of 41 mM [69] to a high of 1321 mM [65], with a mean value of 350 ± 380 mM. The median value was 186 mM.…”

Section: Amino Acid Composition Of Phloem Sapmentioning

confidence: 98%

“…The median value was 186 mM. The large discrepancy between the median and the mean is due to the presence of three values of ≥1000 mM in the data set [65,70]. Fisher reports that the amino acid content of phloem varies from 5 to 40 g/l, consisting primarily of Glu, Asp, Gln and Asn [71].…”

Section: Amino Acid Composition Of Phloem Sapmentioning

confidence: 98%

“…This allows for the collection of undiluted phloem sap, so that one can measure directly the concentrations of the amino acids and other phloem components. However, the volume collected from each stylet is typically 10 to 150 nL [61,[63][64][65], and evaporation from these very small samples can alter the component concentrations [59,62,66].…”

Section: Introductionmentioning

confidence: 99%

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A speciation model of essential trace metal ions in phloem

Harris

Sammons

Grabiak

2012

Journal of Inorganic Biochemistry

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“…There is factual evidence of an existing relationship between amino acid composition and performance of phloem-feeding herbivores (Weibull 1988;Sandstro¨m & Pettersson 1994). According to Karley et al (2002), the correlation between RGR of two aphid species (Myzus persicae and Macrosiphum euphorbiae [Thomas]) and amino acid composition in potato plants was robust.…”

Section: The Content Of Amino Acids In the Phloem Sap Of Plants Undermentioning

confidence: 98%

Effects of elevated atmospheric CO₂concentrations on phloem sap composition of spring crops and aphid performance

Oehme

Högy

Zebitz

et al. 2013

Journal of Plant Interactions

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The concentration and composition of free amino acids and carbohydrates in the phloem sap of wheat and oilseed rape (OSR) and the effects on the performance of aphids (Rhopalosiphum padi and Myzus persicae) were determined under atmospheric carbon dioxide (CO 2 ) enrichment. The analysis of phloem sap showed that carbohydrates and amino acid levels of the host plants were significantly affected by elevated CO 2 level. Among carbohydrate concentrations in the phloem sap, significant increases were observed in fructose and glucose in spring wheat under CO 2 enrichment, whereas no changes were observed in OSR. These changes in plant chemistry affected the performance of herbivorous insects (i.e. aphids) in varying ways, positively affecting the relative growth rate (RGR) of R. padi in spring wheat and negatively affecting the RGR of M. persicae on OSR.

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Free amino acids in the phloem sap from oats and barley resistant to Rhopalosiphum padi

Cited by 57 publications

References 23 publications

How nutritionally imbalanced is phloem sap for aphids?

How nutritionally imbalanced is phloem sap for aphids?

A speciation model of essential trace metal ions in phloem

Effects of elevated atmospheric CO₂concentrations on phloem sap composition of spring crops and aphid performance

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Free amino acids in the phloem sap from oats and barley resistant to Rhopalosiphum padi

Cited by 57 publications

References 23 publications

How nutritionally imbalanced is phloem sap for aphids?

How nutritionally imbalanced is phloem sap for aphids?

A speciation model of essential trace metal ions in phloem

Effects of elevated atmospheric CO2concentrations on phloem sap composition of spring crops and aphid performance

Contact Info

Product

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Effects of elevated atmospheric CO₂concentrations on phloem sap composition of spring crops and aphid performance