562 / 2019-03-17 20:46:51

Role of phytohormone auxin in stem cells differentiation in shoot apical meristem of Arabidopsis thaliana.

Auxin, Shhot apical meristem,Arabidopsis thaliana

全体主题 > Hormones

Higher plants can continuously form new tissues and organs through the differentiation of pluripotent stem cells that are maintained in the meristem. The shoot and root apical meristems are present at the two opposite ends of the plant body. From shoot apical meristem (SAM), all above ground organs are derived including leaf and flowers. The rate of stem cell proliferation in the central zone of SAM is precisely controlled by CLAVATA-WUSCHEL feedback loop. However, it is still not understood how stem cell progenitors enter into differentiation in the periphery of the SAM. Studies both in animals and plants found that key transcription factors (TFs) that are involved in lateral organs differentiation are negatively regulated by the stem cell promoting factors in the stem cell niche to promotes stemness. Previous studies show PIN1 mediated auxin transport plays a critical role in organogenesis in SAM. Here, our genetic studies suggest that not only PIN1 mediated auxin transport, but also TAA1 and TAR2 mediated auxin biosynthesis is critical for stem cell differentiation and organogenesis in SAM. We also found that not only WUS-CLV3 feedback loop but WUS mediated repression of Auxin biosynthesis genes in the stem cell niche is required for maintaining the stem cells homeostasis.