Auxin is an essential hormone for many aspects of plant growth and development. The general goal of this proposal is to elucidate the molecular mechanisms by which auxin regulates various developmental processes. We approached key questions in auxin biology by first elucidating the molecular mechanisms of auxin biosynthesis. We have unambiguously established the first complete tryptophan (Trp)-dependent auxin biosynthesis pathway. Plants use a two-step pathway to convert Trp into Indole-3-acetic acid (IAA), the main auxin in plants. Trp is first converted to indole-3-pyruvate (IPA) by the TAA family of amino transferases and subsequently, IPA is converted to IAA by the YUC family of flavin-containing monooxygenases. The TAA/YUC pathway is the major auxin biosynthesis pathway in plants. By screening for genetic modifiers of auxin biosynthesis mutants, we firmly established a novel signal transduction pathway for auxin-mediated organogenesis. The known components in the signaling pathway are: the protein kinase PID, the scaffolding protein NPY1, and the transcription factor ARF5. Our progress in auxin biosynthesis enables us to modulate auxin levels in plants with spatial and temporal control, thus allowing us to address key questions in auxin biology from a different perspective. The main aims of the proposed studies are: (1) Assess the relative contributions of local auxin biosynthesis and polar auxin transport to Arabidopsis root development; (2) Elucidate the roles of the protein kinase SKA1 in auxin-mediated organogenesis; (3) Genetically delineate the signaling pathway by which auxin controls flower development. The proposed experiments will lead to a more complete picture of the roles of localized auxin biosynthesis in plant development. The proposed work will also provide significant new insights into the signaling mechanisms that control complex developmental processes.

Public Health Relevance

The proposed research is aimed to elucidate the molecular mechanisms by which auxin controls various plant developmental processes. The proposed research will improve our understanding of complex signal transduction mechanisms governing organogenesis and other developmental processes in eukaryotes including humans.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM114660-03
Application #
9204843
Study Section
Development - 1 Study Section (DEV1)
Program Officer
Gibbs, Kenneth D
Project Start
2015-04-01
Project End
2019-01-31
Budget Start
2017-02-01
Budget End
2018-01-31
Support Year
3
Fiscal Year
2017
Total Cost
$268,537
Indirect Cost
$95,287
Name
University of California San Diego
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
He, Yubing; Zhang, Tao; Yang, Ning et al. (2017) Self-cleaving ribozymes enable the production of guide RNAs from unlimited choices of promoters for CRISPR/Cas9 mediated genome editing. J Genet Genomics 44:469-472
Yang, Ning; Wang, Rongchen; Zhao, Yunde (2017) Revolutionize Genetic Studies and Crop Improvement with High-Throughput and Genome-Scale CRISPR/Cas9 Gene Editing Technology. Mol Plant 10:1141-1143
Zhang, Tao; Gao, Yangbin; Wang, Rongchen et al. (2017) Production of Guide RNAs in vitro and in vivo for CRISPR Using Ribozymes and RNA Polymerase II Promoters. Bio Protoc 7:
He, Yubing; Wang, Rongchen; Dai, Xinhua et al. (2017) On Improving CRISPR for Editing Plant Genes: Ribozyme-Mediated Guide RNA Production and Fluorescence-Based Technology for Isolating Transgene-Free Mutants Generated by CRISPR. Prog Mol Biol Transl Sci 149:151-166
Gao, Xiuhua; Chen, Jilin; Dai, Xinhua et al. (2016) An Effective Strategy for Reliably Isolating Heritable and Cas9-Free Arabidopsis Mutants Generated by CRISPR/Cas9-Mediated Genome Editing. Plant Physiol 171:1794-800
Strader, Lucia C; Zhao, Yunde (2016) Auxin perception and downstream events. Curr Opin Plant Biol 33:8-14
Hu, Yun; Zhao, Yunde (2016) Molecular basis for differential light responses in Arabidopsis stems and leaves. Proc Natl Acad Sci U S A 113:5774-6
Dai, Xinhua; Zhang, Yi; Zhang, Da et al. (2015) Embryonic lethality of Arabidopsis abp1-1 is caused by deletion of the adjacent BSM gene. Nat Plants 1:
Hayashi, Ken-Ichiro; Kusaka, Naoyuki; Yamasaki, Soma et al. (2015) Development of 4-methoxy-7-nitroindolinyl (MNI)-caged auxins which are extremely stable in planta. Bioorg Med Chem Lett 25:4464-71
Sugawara, Satoko; Mashiguchi, Kiyoshi; Tanaka, Keita et al. (2015) Distinct Characteristics of Indole-3-Acetic Acid and Phenylacetic Acid, Two Common Auxins in Plants. Plant Cell Physiol 56:1641-54

Showing the most recent 10 out of 11 publications