Phosphate acquisition efficiency in wheat is related to root:shoot ratio, strigolactone levels, and PHO2 regulation. (30th July 2019)

• Record Type: Journal Article
• Authors: de Souza Campos, Pedro M; Cornejo, Pablo; Rial, Carlos; Borie, Fernando; Varela, Rosa M; Seguel, Alex; López-Ráez, Juan Antonio
• Editors: Sunkar, Ramanjulu
• Is Part Of: Journal of experimental botany. Volume 70:Number 20(2019)
• Page Start: 5631
• Page End: 5642
• Publication Date: 2019-07-30
• Subjects: P signalling -- phosphate starvation responses -- phosphate transporters -- root traits -- strigolactones -- wheat; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/erz349
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : Higher Pi acquisition efficiency in wheat was related to an improved root system under Pi starvation, allowing higher Pi uptake. This response correlated with faster modulation of the IPS1 –miR399– PHO2 pathway and strigolactone levels. Abstract: Inorganic phosphorus (Pi) fertilizers are expected to become scarce in the near future; so, breeding for improved Pi acquisition-related root traits would decrease the need for fertilizer application. This work aimed to decipher the physiological and molecular mechanisms underlying the differences between two commercial wheat cultivars (Crac and Tukan) with contrasting Pi acquisition efficiencies (PAE). For that, four independent experiments with different growth conditions were conducted. When grown under non-limiting Pi conditions, both cultivars performed similarly. Crac was less affected by Pi starvation than Tukan, presenting higher biomass production, and an enhanced root development, root:shoot ratio, and root efficiency for Pi uptake under this condition. Higher PAE in Crac correlated with enhanced expression of the Pi transporter genes TaPht1;2 and TaPht1;10 . Crac also presented a faster and higher modulation of the IPS1 –miR399– PHO2 pathway upon Pi starvation. Interestingly, Crac showed increased levels of strigolactones, suggesting a direct relationship between this phytohormone and plant P responses. Based on these findings, we propose that higher PAE of the cultivar Crac is associated with an improved P signalling through a fine-tuning modulation of PHO2 activity, which seems to be regulated by strigolactones. This knowledge will help to develop new strategies for improved plant performance under P stress conditions.