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1-Aminocyclopropane-1-carboxylic acid (ACC) concentration and ACC synthase expression in soybean roots, root tips, and soybean cyst nematode (Heterodera glycines)-infected roots.

Tucker ML, Xue P, Yang R - J. Exp. Bot. (2009)

Bottom Line: In addition, an ACS-like sequence was found in the public SCN nucleotide database.Acquisition of a full-length sequence for this mRNA (accession GQ389647) and alignment with transcripts for other well-characterized ACS proteins indicated that the nematode sequence is missing a key element required for ACS activity and therefore probably is not a functional ACS.Moreover, no significant amount of ACC was found in any growth stage of SCN that was tested.

View Article: PubMed Central - PubMed

Affiliation: Soybean Genomics and Improvement Lab, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Ave., Beltsville, MD, USA. mark.tucker@ars.usda.gov

ABSTRACT
Colonization of plant roots by root knot and cyst nematodes requires a functional ethylene response pathway. However, ethylene plays many roles in root development and whether its role in nematode colonization is direct or indirect, for example lateral root initiation or root hair growth, is not known. The temporal requirement for ethylene and localized synthesis of ethylene during the life span of soybean cyst nematode (SCN) on soybean roots was further investigated. Although a significant increase in ethylene evolution was not detected from SCN-colonized roots, the concentration of the immediate precursor to ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), was higher in SCN-colonized root pieces and root tips than in other parts of the root. Moreover, expression analysis of 17 ACC synthase (ACS) genes indicated that a select set of ACS genes is expressed in SCN-colonized root pieces that is clearly different from the set of genes expressed in non-colonized roots or root tips. Semi-quantitative real-time PCR indicated that ACS transcript accumulation correlates with the high concentration of ACC in root tips. In addition, an ACS-like sequence was found in the public SCN nucleotide database. Acquisition of a full-length sequence for this mRNA (accession GQ389647) and alignment with transcripts for other well-characterized ACS proteins indicated that the nematode sequence is missing a key element required for ACS activity and therefore probably is not a functional ACS. Moreover, no significant amount of ACC was found in any growth stage of SCN that was tested.

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Related in: MedlinePlus

Ethylene synthesis by SCN-inoculated and non-inoculated soybean roots cultured on Gamborg's B5 medium plus organics and 20% sucrose.
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fig1: Ethylene synthesis by SCN-inoculated and non-inoculated soybean roots cultured on Gamborg's B5 medium plus organics and 20% sucrose.

Mentions: Ethylene synthesis was measured at 7 d intervals in control, non-inoculated roots (no SCNs) and SCN-inoculated roots grown on Gamborg's medium containing sucrose. Each flask averaged 114 swollen females on two root systems per flask (∼1 g of roots per flask). Ethylene production was highest on the seventh day and remained steady until 21 d in the control roots (Fig. 1, No SCN), and thereafter steeply declined. The same pattern was observed in the SCN-infected roots, however, with consistently lower values (Fig. 1, Plus SCN). SCN colonization slightly inhibited root growth and, although the ethylene synthesis was normalized to root weight, the infected roots consistently produced slightly lower levels of ethylene than non-infected roots.


1-Aminocyclopropane-1-carboxylic acid (ACC) concentration and ACC synthase expression in soybean roots, root tips, and soybean cyst nematode (Heterodera glycines)-infected roots.

Tucker ML, Xue P, Yang R - J. Exp. Bot. (2009)

Ethylene synthesis by SCN-inoculated and non-inoculated soybean roots cultured on Gamborg's B5 medium plus organics and 20% sucrose.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2803212&req=5

fig1: Ethylene synthesis by SCN-inoculated and non-inoculated soybean roots cultured on Gamborg's B5 medium plus organics and 20% sucrose.
Mentions: Ethylene synthesis was measured at 7 d intervals in control, non-inoculated roots (no SCNs) and SCN-inoculated roots grown on Gamborg's medium containing sucrose. Each flask averaged 114 swollen females on two root systems per flask (∼1 g of roots per flask). Ethylene production was highest on the seventh day and remained steady until 21 d in the control roots (Fig. 1, No SCN), and thereafter steeply declined. The same pattern was observed in the SCN-infected roots, however, with consistently lower values (Fig. 1, Plus SCN). SCN colonization slightly inhibited root growth and, although the ethylene synthesis was normalized to root weight, the infected roots consistently produced slightly lower levels of ethylene than non-infected roots.

Bottom Line: In addition, an ACS-like sequence was found in the public SCN nucleotide database.Acquisition of a full-length sequence for this mRNA (accession GQ389647) and alignment with transcripts for other well-characterized ACS proteins indicated that the nematode sequence is missing a key element required for ACS activity and therefore probably is not a functional ACS.Moreover, no significant amount of ACC was found in any growth stage of SCN that was tested.

View Article: PubMed Central - PubMed

Affiliation: Soybean Genomics and Improvement Lab, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Ave., Beltsville, MD, USA. mark.tucker@ars.usda.gov

ABSTRACT
Colonization of plant roots by root knot and cyst nematodes requires a functional ethylene response pathway. However, ethylene plays many roles in root development and whether its role in nematode colonization is direct or indirect, for example lateral root initiation or root hair growth, is not known. The temporal requirement for ethylene and localized synthesis of ethylene during the life span of soybean cyst nematode (SCN) on soybean roots was further investigated. Although a significant increase in ethylene evolution was not detected from SCN-colonized roots, the concentration of the immediate precursor to ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), was higher in SCN-colonized root pieces and root tips than in other parts of the root. Moreover, expression analysis of 17 ACC synthase (ACS) genes indicated that a select set of ACS genes is expressed in SCN-colonized root pieces that is clearly different from the set of genes expressed in non-colonized roots or root tips. Semi-quantitative real-time PCR indicated that ACS transcript accumulation correlates with the high concentration of ACC in root tips. In addition, an ACS-like sequence was found in the public SCN nucleotide database. Acquisition of a full-length sequence for this mRNA (accession GQ389647) and alignment with transcripts for other well-characterized ACS proteins indicated that the nematode sequence is missing a key element required for ACS activity and therefore probably is not a functional ACS. Moreover, no significant amount of ACC was found in any growth stage of SCN that was tested.

Show MeSH
Related in: MedlinePlus