EAPSI: Investigating Stem Elongation as a Means to Increase Crop Productivity

作为固着生物，植物需要有效地感知和响应环境才能生存。他们实现这一目标的一种方式是通过对光的感知和反应。参与调节光介导的反应的一组关键蛋白是AHLs，一组影响幼苗茎伸长的DNA结合蛋白。茎伸长是许多作物植物发育的第一个关键步骤之一。随着气候的不断变化，更好地了解如何控制茎的伸长对我们来说越来越重要，因为这将有助于改进能够应对这种变化的作物品种。这个EAPSI奖学金将使进一步调查AHLs在茎伸长中的作用，以及这种伸长如何进一步受到植物激素的调节。本研究将在RIKEN研究所进行，由植物细胞研究领域的专家杉本惠子博士指导，以拟南芥为模型系统，以了解光对幼苗生长的影响为主要目的。参与这一过程的一组关键基因是AT-钩基序核定位（AHL）基因家族。AHL 29/植色素B-4的支持子（SOB 3）在幼苗发育过程中直接调节生长素相关基因YUCCA 8（YUC 8）和小生长素UP RNA 19（SAUR 19）亚家族成员。SOB3能够至少部分地通过抑制上述基因的转录来调节幼苗中的下胚轴伸长。由于YUC 8和SAUR 19亚家族的成员直接参与植物激素途径，因此ChIP-Seq将用于测试SOB3与植物特异性激素途径相关的其他基因的启动子结合的假设，如赤霉素，细胞分裂素和茉莉酸。此外，还将使用sob突变体和上述激素进行下胚轴伸长试验，以进一步研究这些相互作用。该奖项是东亚和太平洋夏季研究所计划下的一个奖项，由NSF和日本科学促进会共同资助，支持美国研究生的夏季研究。

As sessile organisms, plants need to effectively sense and respond to their environment in order to survive. One way they accomplish this is through the perception and response to light. A key group of proteins involved in modulating light-mediated responses are the AHLs, a group of DNA-binding proteins that influence stem elongation in seedlings. Stem elongation is among the first crucial steps in plant development for many crop plants. As the climate continues to change, it is increasingly important for us to gain a better understanding of how stem elongation is controlled, as it will facilitate the improvement of crop varieties that can cope with such changes. This EAPSI fellowship will enable further investigation into the role AHLs play in stem elongation, and how this elongation is further regulated by plant hormones. This research will be conducted at the RIKEN Institute under the direction of Dr. Keiko Sugimoto, a leading expert in plant cell research.Using Arabidopsis as a model system, the overarching goal of this research is to understand how light mediates seedling growth. One key group of genes involved in this process is the AT-HOOK MOTIF NUCLEAR LOCALIED (AHL) gene family. AHL29/SUPRESSOR OF PHYTOCHROME B-4 (SOB3) directly regulates the auxin-associated genes YUCCA8 (YUC8) and members of the SMALL AUXIN UP RNA 19 (SAUR19) subfamily during seedling development. SOB3 is able to modulate hypocotyl elongation in seedlings, at least in part, by repressing transcription of the aforementioned genes. Since YUC8 and members of the SAUR19 subfamily are directly involved in phytohormone pathways, ChIP-Seq will be used to test the hypothesis that SOB3 binds to the promoters of additional genes associated with plant-specific hormone pathways, such as gibberellic acid, cytokinins, and jasmonic acid. Additionally, hypocotyl elongation assays will be performed using sob mutants and the aforementioned hormones to further investigate these interactions.This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.