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ORIGINAL RESEARCH article

Front. Plant Sci.
Sec. Plant Development and EvoDevo
Volume 15 - 2024 | doi: 10.3389/fpls.2024.1466431

A Medicago truncatula HD-ZIP gene MtHB2 is involved in modulation of root development by regulating auxin response

Provisionally accepted
Wei Yan Wei Yan 1Runze Wang Runze Wang 2Yutong Zhang Yutong Zhang 3Xiuxiu Zhang Xiuxiu Zhang 4Qin Wang Qin Wang 2*
  • 1 Inner Mongolia Academy of Science and Technology, Hohhot, Inner Mongolia Autonomous Region, China
  • 2 Binzhou Medical University, Binzhou, Shandong Province, China
  • 3 Inner Mongolia Agricultural University, Hohhot, Inner Mongolia Autonomous Region, China
  • 4 Chinese Academy of Sciences (CAS), Beijing, Beijing, China

The final, formatted version of the article will be published soon.

    HD-Zip proteins are plant-specific transcription factors known for their diverse functions in regulating plant growth, development, and responses to environmental stresses. Among the Medicago truncatula HD-Zip II genes, MtHB2 has been previously linked to abiotic stress responses. In this study, we conducted a functional characterization of MtHB2 in the regulation of root growth and development. Upon auxin stimulation, expression of MtHB2 was promptly up-regulated. Overexpression of MtHB2 in Arabidopsis thaliana led to reduced primary root growth and inhibited lateral root formation. Interestingly, the transgenic plants expressing MtHB2 exhibited differential responses to three types of auxins (IAA, NAA, and 2,4-D) in terms of root growth and development compared to the wild-type plants. Specifically, primary root growth was less affected, and lateral root formation was enhanced in the transgenic plants when exposed to auxins. This differential response suggests a potential role for MtHB2 in modulating auxin transport and accumulation, as evidenced by the reduced sensitivity of the transgenic plants to the auxin transport inhibitor NPA and lower expression levels of auxin-related reporters such as PIN-FORMED (PIN1)::PIN1-GFP,

    Keywords: auxin, HD-ZIP II, MtHB2, Medicago truncatula, root development

    Received: 18 Jul 2024; Accepted: 05 Sep 2024.

    Copyright: © 2024 Yan, Wang, Zhang, Zhang and Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Qin Wang, Binzhou Medical University, Binzhou, 256603, Shandong Province, China

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