TDR INTERACTING PROTEIN 3, encoding a PHD‐finger transcription factor, regulates Ubisch bodies and pollen wall formation in rice

Abstract

Summary Male reproductive development involves a complex series of biological events and precise transcriptional regulation is essential for this biological process in flowering plants. Several transcriptional factors have been reported to regulate tapetum and pollen development, however the transcriptional mechanism underlying Ubisch bodies and pollen wall formation remains less understood. Here, we characterized and isolated a male sterility mutant of TDR INTERACTING PROTEIN 3 (TIP3) in rice. The tip3 mutant displayed smaller and pale yellow anthers without mature pollen grains, abnormal Ubisch body morphology, no pollen wall formation, as well as delayed tapetum degeneration. Map‐based cloning demonstrated that TIP3 encodes a conserved PHD‐finger protein and further study confirmed that TIP3 functioned as a transcription factor with transcriptional activation activity. TIP3 is preferentially expressed in the tapetum and microspores during anther development. Moreover, TIP3 can physically interact with TDR, which is a key component of the transcriptional cascade in regulating tapetum development and pollen wall formation. Furthermore, disruption of TIP3 changed the expression of several genes involved in tapetum development and degradation, biosynthesis and transport of lipid monomers of sporopollenin in tip3 mutant. Taken together, our results revealed an unprecedented role for TIP3 in regulating Ubisch bodies and pollen exine formation, and presents a potential tool to manipulate male fertility for hybrid rice breeding.

Disruption of EARLY LESION LEAF 1, encoding a cytochrome P450 monooxygenase, induces ROS accumulation and cell death in rice

“…GUS assays were conducted as described previously (Yang et al, 2019). The protocol of the H 2 DCFDA experiment was modified according to the method of Leshem et al (2006).…”

Defective Microspore Development 1 is required for microspore cell integrity and pollen wall formation in rice

“…Previous studies have suggested that the post‐meiotic developmental program of rice anthers is regulated by multiple transcription factors, such as TDR (Li et al ., 2006), GAMYB (Aya et al ., 2009), Undeveloped Tapetum 1 (UDT1) (Jung et al ., 2005), ETERNAL TAPETUM 1 (EAT1) (Niu et al ., 2013), OsMADS3 (Hu et al ., 2011), PERSISTENT TAPETAL CELL 1 (PTC1) (Li et al ., 2011), OsTDF1 (Cai et al ., 2015), TDR INTERACTING PROTEIN 2 (TIP2) (Fu et al ., 2014) and TIP3 (Yang et al ., 2019). Some of these proteins physically interact to finely regulate the development of the microspore and tapetum (Ono et al ., 2018).…”

“…TDR can also physically interact with a PHD‐finger transcription factor, TIP3. The complex containing TDR and TIP3 mainly regulates the formation of pollen exine in rice (Yang et al ., 2019). Here, we revealed that DMD1 can interact with TDR.…”

Exploiting Genic Male Sterility in Rice: From Molecular Dissection to Breeding Applications

“…Finally, the gene TDR INTERACTING PROTEIN3 ( TIP3 ) encodes for a PHD-Finger TF that is expressed during early anther development. tip3 mutants are characterized by defective anther cuticle and pollen wall formation, an abnormal ubisch body morphology, and a delayed degradation of the tapetum ( Yang et al, 2019b ).…”

“…The TDR Interacting Protein 2 ( TIP2 ) and TDR Interacting Protein 3 ( TIP3 ) genes follow the pathway of indirect regulation of target genes. Moreover, TIP2 and TIP3 regulate the expression of the Tapetum Degeneration Retardation ( TDR ) gene ( Fu et al, 2014 ; Ko et al, 2014 ; Yang et al, 2019b ), which, in turn, regulates the expression of other target genes, including OsC6 and OsCYP703A3 , by directly binding to their promoter. Similarly, the gene TGA10 interacts with both TIP2 and TDR and affects the expression of AP25 and MTR1 genes ( Chen et al, 2018 ).…”