DYSFUNCTIONAL TAPETUM 1 (DYT1) (Gu et al., 2014 Zhang et al., 2006), DEFECTIVE IN TAPETAL DEVELOPMENT AND FUNCTION 1 (TDF1) (Gu et al., 2014), ABORTED MICROSPORE (AMS) (Ma et al., 2012 Xu et al., 2014, 2010), and MYB80 (also named MYB103 or Male Sterile 188) (Wang et al., 2018) form a signaling cascade. Several transcription factors have been reported to be critical for pollen development. Eventually, the tapetum gradually degenerates through programmed cell death (PCD) (Luo et al., 2013) and disappears before anther dehiscence. In addition, the tapetum also synthesizes and secretes components such as callase to release the YM from the tetrad (Mepham and Lane, 1969) and sporopollenin for the formation of the outer pollen wall (also called exine) (Gu et al., 2014 Xu et al., 2014), as well as neutral lipids for the pollen coat formation. The tapetum encloses the locule to provide space and nutrients for pollen development. Finally, the BN pollen undergoes further mitosis to form the tricellular (TC) pollen. Next, the VP undergoes mitosis to become binuclear (BN). After release from the tetrad, the young microspores (YMs) expand and form vacuolated pollen (VP) with a large vacuole inside. Pollen development in Arabidopsis starts from a pollen mother cell (PMC) that undergoes meiosis to produce a tetrad of four haploid microspores. Seed production and the majority of our food supply rely on the success of sexual reproduction, which requires viable pollen and ovules. To sum up, Fe deficiency in anthers may affect Fe‐dependent protein function and impact upstream transcription factors and their downstream genes, resulting in extensively impaired tapetum function and pollen development. Since DEGs in Fe‐deficient anthers were not significantly enriched in genes related to mitochondrial function, the changes in mitochondrial status under Fe deficiency, including respiration activity, density, and morphology, were probably because the Fe amount was insufficient to maintain proper mitochondrial protein function in anthers. Analysis of RESPIRATORY‐BURST OXIDASE HOMOLOG E (RBOHE) gain‐ and loss‐of‐function under Fe deficiency indicated that RBOHE‐ and Fe‐dependent regulation cooperatively control anther reactive oxygen species levels and pollen development. Co‐expression analysis revealed that ABORTED MICROSPORES ( AMS), DEFECTIVE IN TAPETAL DEVELOPMENT AND FUNCTION1, and BASIC HELIX‐LOOP‐HELIX 089/ 091/ 010 encode key upstream transcription factors of Fe deficiency‐responsive DEGs involved in tapetum function and development, including tapetal ROS homeostasis, programmed cell death, and pollen outer wall formation‐related lipid metabolism. A comparison of differentially expressed genes (DEGs) in Fe‐deficient leaves, roots, and anthers suggested that changes in several cellular processes were unique to anthers, including increased lipid degradation. Here, plants transferred to Fe‐deficient medium at the reproductive stage had reduced floral Fe content and viable pollen and showed a defective pollen outer wall, all restored by supplying floral buds with Fe. How Fe insufficiency in floral buds affects pollen development remains unexplored. Reduction of crop yield due to iron (Fe) deficiency has always been a concern in agriculture.

Statistical analysis of H 2DCFDA fluorescence intensity in Fe‐sufficient and ‐deficient anthers at each developmental stage in different lines.

GO enrichment analysis of tapetum‐expressed genes induced by Fe deficiency and also differentially expressed in the tdf1, ams, and bhlhs mutants.ĭata S1. Anther‐unique DEGs under Fe deficiency in the phenylpropanoid biosynthesis pathway. Pathway enrichment analysis of anther‐unique DEGs under Fe deficiency. The DEGs in anthers, leaves, and roots under Fe deficiency. Element contents in leaves and floral buds. 3D numerical analysis of mitochondrial morphology. Mitochondria labeled with mito‐GFP in isolated tapetal cells.įigure S10. The activities and protein abundance of mitochondrial respiratory complexes in developing anthers under Fe deficiency.įigure S9. The effect of RBOHE expression on anther ROS levels under Fe sufficiency and deficiency.įigure S8. Analysis of the expression of genes that are repressed in anther tissue upon Fe deficiency in the tapetal transcriptomes of ams, tdf1, and bhlhs mutants.įigure S7. The changes in transcript levels of known −Fe genes, DYT1 and MYB80, in anthers under Fe deficiency.įigure S6.

The workflow of Fe‐deficient anther transcriptome analysis.įigure S5. Cryo‐SEM images of pollen in dehiscent anthers.įigure S4. DNA fragmentation in Fe‐sufficient and ‐deficient anthers.įigure S3. The morphology of plants and in vitro germination of pollen grown under Fe‐sufficient and ‐deficient conditions.įigure S2.

Automatic bud trimmer homemade