Page 16 - S. Plant biology

[S. Plant biology-9]

Regulation of stomatal development by stomatal lineage

miRNAs

Jiali Zhu¹, Ji-Hwan Park²˙³, Jaeho Lee¹˙², Daehee Hwang²˙⁴, Yun Ju Kim², June M Kwak¹

¹New Biology, DGIST, Daegu 42988, Republic of Korea, ²Center for Plant Aging Research, IBS, Daegu 42988,

Republic of Korea, ³Korean Bioinformation Center, KRIBB, Daejeon 34141, Republic of Korea, ⁴School of Biological
Science, Seoul National Univ. , Seoul 08826, Republic of Korea

Stomata in the plant epidermis play a critical role in growth and survival by controlling gas exchange, transpiration,

and immunity to pathogens. Plants modulate stomatal cell fate and patterning through key transcriptional factors

and signaling pathways. miRNAs are known to contribute to developmental plasticity in multicellular organisms,
however, no miRNAs appear to target the known regulators of stomatal development. It remains unclear as to
whether miRNAs are involved in stomatal development. Here, we report highly dynamic, developmentally stage-

specific miRNA expression profiles from stomatal lineage cells. We demonstrate that stomatal lineage miRNAs
positively and negatively regulate stomatal formation and patterning to avoid clustered stomata. Target prediction

of stomatal lineage miRNAs implicates potential cellular processes in stomatal development. We show that
miR399-mediated PHO2 regulation, involved in phosphate homeostasis, contributes to the control of stomatal

development. Our study demonstrates that miRNAs constitute a critical component in the regulatory mechanisms
controlling stomatal development.