553 / 2019-03-15 21:06:20

GENETIC CONTROL OF IRON LOADING IN Arabidopsis EMBRYOS

Iron,nutrition,transcription-factor,B3-transcription-factor

全体主题 > Nutrition

The molecular mechanisms that regulate iron (Fe) allocation in plant seeds are poorly understood. It has been shown that Fe accumulates in endodermis, a cell layer that surrounds provasculature, during Arabidopsis embryo maturation. To better understand the genetic control of Fe accumulation and distribution in seed embryo, we used mutants in transcription factors known involved in embryo development and seed maturation. We initially focus on FUSCA3 (FUS3), ABSCISIC ACID INSENSITIVE3 (ABI3) and LEAFY COTYLEDON2 (LEC2) mutants. These three genes encode transcription factors belong to the B3 containing domain family.
We analyzed the distribution of Fe using Perls/DAB staining. In fus3 and abi3 mutants, Fe seems to be misallocated. Fe is not detected in cotyledons of lec2 mutant. Interestingly, these three mutant seeds have the same total Fe content (measured by ICP-MS). We also studied through a Gene Regulatory Network (GRN) new relations between the B3 transcription factors and different genes related to Fe homeostasis. Using qRT-PCR, we analyzed the expression of critical genes in Fe homeostasis. Mainly, we focus on FERRITINs genes, which expression is deregulated in B3 mutant seeds at mRNA and protein level.
Our results indicate that B3 transcription factors, LEC2, FUS3, and ABI3 have a relevant role in Fe accumulation and distribution in Arabidopsis embryos.

This work was funded by FONDECYT 1160334, ECOS180017/ PC18B08, and CONICYT-PFCHA/Doctorado Nacional/2017-21170951.