SHOOT MERISTMLESS (STM) encoding a homeodomain protein plays a vital role in the specification of shoot meristem, the source of undifferentiated cells for the above-ground organ development in Arabidopsis thaliana. The roles of STM still remain to be elucidated as stm is deficient in the late organ development. Here, we have isolated a recessive filamentous gynoecium (fig)-1 displaying slightly reduced floral meristem and weak sepal fusion defect by introducing the 35S enhancer tag into the poltergeist-6. A truncated tag was localized at the 4628 base pairs (bps) upstream from the STM start codon in fig-1 led to the decrease in the STM transcripts. Two additional knocked-down mutant alleles, stm-p1 and stm-p3 harboring T-DNA insertions at 468 and 2225 bps upstream from the start codon, respectively displayed the pennywise (pny)-like clustered internode together with the sepal fusion defects. In stm-p1, the expression of KNOTTED-1 LIKE FROM A. THALIANA6 was enhanced and stm-p1 brevipedicelus-1 developed extremely compact internodes. The sepal fusion phenotypes of stm-p1 and stm-p3 were comparable to that of cup-shaped cotyledon1 (cuc1) and CUC1 expression was reduced in stm-p1. Together, these results suggest that STM functions genetically in association with PNY and CUC1 for the proper inflorescence development and the sepal separation, respectively.
Bibliographical noteFunding Information:
This work was supported by a grant from the Basic Science Research Program through the National Research Foundation (Grant number, 2018R1A6A1A03025607) funded by the Ministry of Education, Republic of Korea to M.M.L., and research funds from Chosun University 2014 (K206888001) and 2015 (K206888002) to S.S.
All Science Journal Classification (ASJC) codes
- Plant Science