Végh Attila, Incze Norbert, Fábián Attila, Huo Heqiang, Bradford Kent J, Balázs Ervin, Soós Vilmos
Department of Applied Genomics, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of SciencesMartonvasar, Hungary.
Department of Plant Cell Biology, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of SciencesMartonvasar, Hungary.
Front Plant Sci. 2017 Sep 22;8:1641. doi: 10.3389/fpls.2017.01641. eCollection 2017.
Strigolactones (SLs) and related butenolides, originally identified as active seed germination stimulants of parasitic weeds, play important roles in many aspects of plant development. Two members of the D14 α/β hydrolase protein family, DWARF14 (D14) and KARRIKIN INSENSITIVE2 (KAI2) are essential for SL/butenolide signaling. The third member of the family in Arabidopsis, DWARF 14-LIKE2 (DLK2) is structurally very similar to D14 and KAI2, but its function is unknown. We demonstrated that DLK2 does not bind nor hydrolyze natural (+)5-deoxystrigol [(+)5DS], and weakly hydrolyzes non-natural strigolactone (-)5DS. A detailed genetic analysis revealed that DLK2 does not affect SL responses and can regulate seedling photomorphogenesis. is upregulated in the dark dependent upon KAI2 and PHYTOCHROME INTERACTING FACTORS (PIFs), indicating that DLK2 might function in light signaling pathways. In addition, unlike its paralog proteins, DLK2 is not subject to -GR24-induced degradation, suggesting that DLK2 acts independently of MORE AXILLARY GROWTH2 (MAX2); however, regulation of DLK2 transcription is mostly accomplished through MAX2. In conclusion, these data suggest that DLK2 represents a divergent member of the DWARF14 family.
独脚金内酯（SLs）及相关的丁烯内酯最初被鉴定为寄生杂草种子萌发的活性刺激物，在植物发育的许多方面发挥着重要作用。D14 α/β水解酶蛋白家族的两个成员，DWARF14（D14）和KARRIKIN INSENSITIVE2（KAI2）对SL/丁烯内酯信号传导至关重要。拟南芥中该家族的第三个成员DWARF 14-LIKE2（DLK2）在结构上与D14和KAI2非常相似，但其功能尚不清楚。我们证明DLK2既不结合也不水解天然的（+）5-脱氧独脚金醇[（+）5DS]，并且只能微弱地水解非天然独脚金内酯（-）5DS。详细的遗传分析表明，DLK2不影响SL反应，但可以调节幼苗的光形态建成。DLK2在黑暗中受KAI2和光敏色素相互作用因子（PIFs）的调控而上调，这表明DLK2可能在光信号通路中发挥作用。此外，与它的旁系同源蛋白不同，DLK2不会受到-GR24诱导的降解，这表明DLK2独立于多侧芽生长2（MAX2）发挥作用；然而，DLK2转录的调控大多是通过MAX2完成的。总之，这些数据表明DLK2是D14家族中一个不同的成员。
