The MYB transcription factor TaPHR3-A1 is involved in phosphate signaling and governs yield-related traits in bread wheat

Abstract

Improved inorganic phosphate (Pi) use efficiency in crops will be important for sustainable agriculture. Exploring molecular mechanisms that regulate Pi uptake could provide useful information for breeding wheat with improved Pi use efficiency. Here, a TaPHR3-A1 (Gene ID: TraesCS7A02G415800), ortholog of rice OsPHR3 that functions in transcriptional regulation of Pi signaling, was cloned from wheat chromosome 7A. Ectopic expression of TaPHR3-A1 in Arabidopsis and rice gave in enhanced vegetative growth and more seeds. Overexpression in transgenic rice led to increased biomass, grain number and primary panicle branching by 61.23%, 42.12% and 36.34% compared to the wild type. Transgenic wheat lines with down regulated TaPHR3-A1 exhibited retarded growth and root hair development at the seedling stage, and showed yield-related effects at the adult stage when grown in both low and sufficient Pi conditions, indicating that TaPHR3-A1 positively regulated tolerance to low-Pi. Introgression lines further confirmed the effect of TaPHR3-A1 in improving grain number. The Chinese wheat mini core collection and a recombinant inbred line analysis demonstrated that favorable allele TaPHR3-A1-A associated with higher grain number was positively selected in breeding. A TaPHR3-A1-dCAPS marker effectively identified haplotype TaPHR3-A1-A. Our results suggested that TaPHR3-A1 was a functional regulatory factor for Pi uptake and provided useful information for marker-assisted selection for high yield in wheat.

Two high hierarchical regulators, PuMYB40 and PuWRKY75, control the low phosphorus driven adventitious root formation in Populus ussuriensis

“…Phytohormone signallings of LR and AR formation have been evidenced to be subject to the regulatory mechanisms in which TFs are the major players (Bellini et al ., 2014 ; Crombez et al ., 2019 ). Among Pi starvation‐related TFs, PHOSPHATE RESPONSE 1 (PHR1), a MYB coiled‐coil domain TF (Dubos et al ., 2010 ; Sega and Pacak, 2019 ), is known as the master regulator that mediates phosphate starvation response in Arabidopsis (Devaiah et al ., 2009 ), bread wheat (Zheng et al ., 2020 ), rice (Dai et al ., 2012 ; Rubio et al ., 2001 ), and soybean (Xue et al ., 2017 ); thousands of phytohormone signalling factors and many other LR‐related TFs have been identified to be the direct targets of PHR1 (Castrillo et al ., 2017 ). PHR1 and related TFs have been suggested to be the major players in Pi‐starvation‐induced LR formation (Crombez et al ., 2019 ).…”

Identification of Candidate Genes for Root Traits Using Genotype–Phenotype Association Analysis of Near-Isogenic Lines in Hexaploid Wheat (Triticum aestivum L.)

“…Other grain-related QTL in cereals overlapped marker Xbarc121, a flanking marker of QHtscc.ksu-7A. Several QTL controlling thousand-grain weight and grain number in bread wheat for grain weight per plant in durum wheat, panicle number, seed setting rate, and grain weight per plant in rice also overlapped Xbarc121 and therefore QHtscc.ksu-7A [35,36].…”

“…MYB transcription factor (TF) encoding genes in wheat, such as TaPHR3-A1 and TaSIM, improved P uptake, salt stress tolerance, grain number, and notably root length in Arabidopsis [35,50]. A mutant of soybean overexpressing wheat R2R3-MYB TF (GmMYB84) had greater primary rooting depth at optimum reactive oxygen species (ROS) level and drought tolerance [51].…”

Analysis of Wheat Wax Regulation Mechanism by Liposome and Transcriptome

“…Quantitative real-time PCR was performed using SYBR® Premix Ex Taq™ II (Takara) according to the manufacturer’s instructions on a 7,300 Real-time PCR System (Applied Biosystems), where the relative expression of each gene was calculated according to the 2 −ΔΔCT method ( Zheng et al, 2020 ). The glyceraldehyde-3-phosphate dehydrogenase gene was used as an endogenous reference for real-time PCR, and all analyses were performed with three technical and three biological replications.…”