Title : Characterization of NtWoolly and NtRAX2-like two transcription factors involved in the development of glandular trichomes of nicotiana tabacum.
Abstract:
Trichomes, the epidermal outgrowths found on most aerial plant tissues, are prevalent in a vast number of plant species and can be glandular or non-glandular. As multicellular structures that develop post- embryonically, glandular trichomes serve as an excellent model for investigating fundamental aspects of cell development, such as cell fate determination, cell cycle control, division and polarity, differentiation, and cell-to-cell signaling. Despite their importance, there is a significant knowledge gap regarding the regulators of glandular trichome formation and patterning in the leaf epidermis, specifically those governing entry into the glandular trichome cell fate and progression through its developmental pathway. In this study, we focus on the functional characterization of NtWoolly, a HD-ZIPIV transcription factor, and NtRAX2-like, an R2R3 MYB transcription factor. Both genes are specifically expressed in the protoderm (developing epidermis) of leaf primordia, with their expression ceasing in mature leaves. Notably, we discovered that NtRAX2-like and NtWoolly physically interact, suggesting that their heteromerization may promote glandular trichome development. To explore their roles, we performed DAP-seq analysis on both transcription factors, revealing numerous shared direct transcriptional targets, which underscores their potential common transcriptional activation pathway. Among these targets are key regulators known for their involvement in trichome development in other plant species. Additionally, we utilized reverse genetics to generate overexpressing and knockout lines for both transcription factors, yielding significant results in terms of trichome density and the chemical composition on the surface of tobacco leaves. These findings highlight the role of NtWoolly and NtRAX2-like as a transcriptional complex regulating the early stages of glandular trichome development in Nicotiana tabacum.
Audience Take Away Notes:
Trichomes, the epidermal outgrowths found on most aerial plant tissues, are prevalent in a vast number of This research provides valuable insights into the specific mechanisms underlying the development of glandular trichomes, which are critical for various plant functions, including defense against herbivores and pathogens. By uncovering the roles of key transcription factors and signaling pathways, this study advances our understanding of how these specialized structures form and function. From a broader perspective, the research elucidates key factors involved in the differentiation of protodermal cells into complex specialized structures. This knowledge not only enhances our comprehension of trichome development but also sheds light on fundamental processes of cell differentiation and specialization in plants. Additionally, the sequencing analysis conducted in this study offers methodological expertise that can be beneficial to other research groups working on similar topics. This aspect of the research provides a framework for exploring gene expression and regulatory networks in plant development. The reverse genetics approach utilized in this research will be of particular interest to those studying plant development and transcription factors. By manipulating specific genes and observing the resultant phenotypic changes, this approach helps to identify and characterize the functions of genes involved in trichome formation. In the long term, the findings from this work could contribute to the development of crop lines with enhanced resistance to pathogens and herbivores. The increased production of glandular trichomes, as facilitated by the insights gained from this research, could improve the plants' ability to withstand biotic and abiotic stresses, ultimately leading to more resilient agricultural systems
