RUI: Characterization of Arabidopsis Mutants with defects inan Essential Gene Involved in Auxin Response and Early Development

植物激素生长素几乎在植物生长发育的各个方面都起着重要作用，包括芽和根的形成以及对重力和光的反应。生长素通过调节细胞伸长、细胞分裂和细胞分化来影响这些过程。然而，生长素究竟起什么作用，以及它在分子水平上是如何起作用的，人们仍然知之甚少。只有少数基因在生长素反应途径中起作用已被确定。本研究旨在通过对两个未知基因AXR6缺陷的拟南芥突变体的表征和分析，增加我们对生长素功能和作用机制的认识。杂合的axr6突变体具有生长素抗性，矮化和浓密，与生长素敏感性普遍降低一致。纯合子的axr6植物表现出一种生长素相关突变的新表型：它们在幼苗时生长受阻，在茎和根上都有缺陷。这些突变体表型的初步观察表明，AXR6是参与生长素反应和发育调控的重要基因。这项研究将使我们在分子水平上更全面地了解植物的生理和发育，特别是生长素的作用。这样的理解是非常重要的，也应该提高我们以理想的方式调节植物发育的能力。

9632016 Hobbie The plant hormone auxin plays an important role in virtually all aspects of plant growth and development, including formation of shoots and roots and responses to gravity and light. Auxin affects these processes through regulation of cell elongation, cell division, and cell differentiation. However, exactly what auxin does and how it does it at the molecular level are still poorly understood. Only a few genes that act in the auxin response pathway have been identified. This research is designed to increase our knowledge of the function and mechanism of action of auxin by means of characterization and anlysis of two Arabidopsis mutants with defects in a previously-unknown gene called AXR6. Heterozygous axr6 mutants are auxin-resistant, dwarf, and bushy, consistent with a general reduction in auxin sensitivity. Homozygous axr6 plants show a novel phenotype for an auxin-related mutant: they arrest growth as young seedlings, with defects in both shoots and roots. These preliminary observations of the mutants' phenotype suggest that AXR6 is an essential gene involved in auxin response and regulation of development. This research should bring us closer to a complete understanding of plant physiology and development at the molecular level, and especially of the role of auxin. Such an understanding is fundamentally important, and should also enhance our ability to regulate plant development in desirable ways.