TY - JOUR
T1 - Nodule-enriched GRETCHEN HAGEN 3 enzymes have distinct substrate specificities and are important for proper soybean nodule development
AU - Damodaran, Suresh
AU - Westfall, Corey S.
AU - Kisely, Brian A.
AU - Jez, Joseph M.
AU - Subramanian, Senthil
N1 - Funding Information:
This research was supported by funds from the National Science Foundation/EPSCoR Cooperative Agreement #IIA-1355423, National Science Foundation–Plant Genome Research Program award# IOS-1350189, SD Agricultural Experiment Station (H351-09 and H543-15), SD Soybean Research and Promotion Council (SA1400515), South Dakota State University, and the State of South Dakota. Research in the Jez lab was supported by the National Science Foundation (NSF-MCB-1614539 to Joseph M. Jez). Corey S. Westfall was a USDA Predoctoral Fellow (MOW-2010-05240). Brian A. Kisely was a SDSU Bentley-Griffith undergraduate research fellow. Technical assistance from undergraduate lab assistants Kajol Khatri, and Kirstan Hyser (BioSNTR summer undergraduate fellow), and the use of instruments available at South Dakota State University’s Functional Genomics Core Facility supported in part by the National Science Foundation/EPSCoR Grant No. 0091948 and by the State of South Dakota, are gratefully acknowledged.
Funding Information:
Acknowledgments: This research was supported by funds from the National Science Foundation/EPSCoR Cooperative Agreement #IIA-1355423, National Science Foundation–Plant Genome Research Program award# IOS-1350189, SD Agricultural Experiment Station (H351-09 and H543-15), SD Soybean Research and Promotion Council (SA1400515), South Dakota State University, and the State of South Dakota. Research in the Jez lab was supported by the National Science Foundation (NSF-MCB-1614539 to Joseph M. Jez). Corey S. Westfall was a USDA Predoctoral Fellow (MOW-2010-05240). Brian A. Kisely was a SDSU Bentley-Griffith undergraduate research fellow. Technical assistance from undergraduate lab assistants Kajol Khatri, and Kirstan Hyser (BioSNTR summer undergraduate fellow), and the use of instruments available at South Dakota State University’s Functional Genomics Core Facility supported in part by the National Science Foundation/EPSCoR Grant No. 0091948 and by the State of South Dakota, are gratefully acknowledged.
Publisher Copyright:
© 2017 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2017/12
Y1 - 2017/12
N2 - Legume root nodules develop as a result of a symbiotic relationship between the plant and nitrogen-fixing rhizobia bacteria in soil. Auxin activity is detected in different cell types at different stages of nodule development; as well as an enhanced sensitivity to auxin inhibits, which could affect nodule development. While some transport and signaling mechanisms that achieve precise spatiotemporal auxin output are known, the role of auxin metabolism during nodule development is unclear. Using a soybean root lateral organ transcriptome data set, we identified distinct nodule enrichment of three genes encoding auxin-deactivating GRETCHEN HAGEN 3 (GH3) indole-3-acetic acid (IAA) amido transferase enzymes: GmGH3-11/12, GmGH3-14 and GmGH3-15. In vitro enzymatic assays showed that each of these GH3 proteins preferred IAA and aspartate as acyl and amino acid substrates, respectively. GmGH3-15 showed a broad substrate preference, especially with different forms of auxin. Promoter:GUS expression analysis indicated that GmGH3-14 acts primarily in the root epidermis and the nodule primordium where as GmGH3-15 might act in the vasculature. Silencing the expression of these GH3 genes in soybean composite plants led to altered nodule numbers, maturity, and size. Our results indicate that these GH3s are needed for proper nodule maturation in soybean, but the precise mechanism by which they regulate nodule development remains to be explained.
AB - Legume root nodules develop as a result of a symbiotic relationship between the plant and nitrogen-fixing rhizobia bacteria in soil. Auxin activity is detected in different cell types at different stages of nodule development; as well as an enhanced sensitivity to auxin inhibits, which could affect nodule development. While some transport and signaling mechanisms that achieve precise spatiotemporal auxin output are known, the role of auxin metabolism during nodule development is unclear. Using a soybean root lateral organ transcriptome data set, we identified distinct nodule enrichment of three genes encoding auxin-deactivating GRETCHEN HAGEN 3 (GH3) indole-3-acetic acid (IAA) amido transferase enzymes: GmGH3-11/12, GmGH3-14 and GmGH3-15. In vitro enzymatic assays showed that each of these GH3 proteins preferred IAA and aspartate as acyl and amino acid substrates, respectively. GmGH3-15 showed a broad substrate preference, especially with different forms of auxin. Promoter:GUS expression analysis indicated that GmGH3-14 acts primarily in the root epidermis and the nodule primordium where as GmGH3-15 might act in the vasculature. Silencing the expression of these GH3 genes in soybean composite plants led to altered nodule numbers, maturity, and size. Our results indicate that these GH3s are needed for proper nodule maturation in soybean, but the precise mechanism by which they regulate nodule development remains to be explained.
KW - Artificial microRNA
KW - Auxin
KW - Gretchen Hagen 3 (GH3)
KW - Indole-3-acetic acid (IAA)
KW - Nodule
KW - Soybean (Glycine max)
UR - http://www.scopus.com/inward/record.url?scp=85036509316&partnerID=8YFLogxK
U2 - 10.3390/ijms18122547
DO - 10.3390/ijms18122547
M3 - Article
C2 - 29182530
AN - SCOPUS:85036509316
SN - 1661-6596
VL - 18
JO - International journal of molecular sciences
JF - International journal of molecular sciences
IS - 12
M1 - 2547
ER -