Cécile Julia1, Matthias Wissuwa2, Tobias Kretzschmar3, Kwanho Jeong4, Terry Rose1. 1. Southern Cross Plant Science, Southern Cross University, PO Box 57, Lismore, NSW 2480, Australia Southern Cross GeoScience, Southern Cross University, PO Box 57, Lismore, NSW 2480, Australia cecile.julia@scu.edu.au terry.rose@scu.edu.au. 2. Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences, 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan. 3. Genotyping Services Laboratory, International Rice Research Institute (IRRI), DAPO BOX 7777, Metro Manila, Philippines. 4. Southern Cross Plant Science, Southern Cross University, PO Box 57, Lismore, NSW 2480, Australia Southern Cross GeoScience, Southern Cross University, PO Box 57, Lismore, NSW 2480, Australia.
Abstract
BACKGROUNDS AND AIMS: In cultivated rice, phosphorus (P) in grains originates from two possible sources, namely exogenous (post-flowering root P uptake from soil) or endogenous (P remobilization from vegetative parts) sources. This study investigates P partitioning and remobilization in rice plants throughout grain filling to resolve contributions of P sources to grain P levels in rice. METHODS: Rice plants (Oryza sativa 'IR64') were grown under P-sufficient or P-deficient conditions in the field and in hydroponics. Post-flowering uptake, partitioning and re-partitioning of P was investigated by quantifying tissue P levels over the grain filling period in the field conditions, and by employing 33P isotope as a tracer in the hydroponic study. KEY RESULTS: Post-flowering P uptake represented 40-70 % of the aerial plant P accumulation at maturity. The panicle was the main P sink in all studies, and the amount of P potentially remobilized from vegetative tissues to the panicle during grain filling was around 20 % of the total aerial P measured at flowering. In hydroponics, less than 20 % of the P tracer taken up at 9 d after flowering (DAF) was found in the above-ground tissues at 14 DAF and half of it was partitioned to the panicle in both P treatments. CONCLUSIONS: The results demonstrate that P uptake from the soil during grain filling is a critical contributor to the P content in grains in irrigated rice. The P tracer study suggests that the mechanism of P loading into grains involves little direct transfer of post-flowering P uptake to the grain but rather substantial mobilization of P that was previously taken up and stored in vegetative tissues.
BACKGROUNDS AND AIMS: In cultivated rice, phosphorus (P) in grains originates from two possible sources, namely exogenous (post-flowering root P uptake from soil) or endogenous (P remobilization from vegetative parts) sources. This study investigates P partitioning and remobilization in rice plants throughout grain filling to resolve contributions of P sources to grain P levels in rice. METHODS:Rice plants (Oryza sativa 'IR64') were grown under P-sufficient or P-deficient conditions in the field and in hydroponics. Post-flowering uptake, partitioning and re-partitioning of P was investigated by quantifying tissue P levels over the grain filling period in the field conditions, and by employing 33P isotope as a tracer in the hydroponic study. KEY RESULTS: Post-flowering P uptake represented 40-70 % of the aerial plant P accumulation at maturity. The panicle was the main P sink in all studies, and the amount of P potentially remobilized from vegetative tissues to the panicle during grain filling was around 20 % of the total aerial P measured at flowering. In hydroponics, less than 20 % of the P tracer taken up at 9 d after flowering (DAF) was found in the above-ground tissues at 14 DAF and half of it was partitioned to the panicle in both P treatments. CONCLUSIONS: The results demonstrate that P uptake from the soil during grain filling is a critical contributor to the P content in grains in irrigated rice. The P tracer study suggests that the mechanism of P loading into grains involves little direct transfer of post-flowering P uptake to the grain but rather substantial mobilization of P that was previously taken up and stored in vegetative tissues.
Authors: Hannah M Schneider; Johannes A Postma; Tobias Wojciechowski; Christian Kuppe; Jonathan P Lynch Journal: Plant Physiol Date: 2017-06-30 Impact factor: 8.340
Authors: Kwanho Jeong; Cecile C Julia; Daniel L E Waters; Omar Pantoja; Matthias Wissuwa; Sigrid Heuer; Lei Liu; Terry J Rose Journal: PLoS One Date: 2017-11-02 Impact factor: 3.240
Authors: Kwanho Jeong; Omar Pantoja; Abdul Baten; Daniel Waters; Tobias Kretzschmar; Matthias Wissuwa; Cecile C Julia; Sigrid Heuer; Terry J Rose Journal: PLoS One Date: 2018-09-13 Impact factor: 3.240