BACKGROUND AND AIMS: Leafy vegetable Brassica crops are an important source of dietary calcium (Ca) and magnesium (Mg) and represent potential targets for increasing leaf Ca and Mg concentrations through agronomy or breeding. Although the internal distribution of Ca and Mg within leaves affects the accumulation of these elements, such data are not available for Brassica. The aim of this study was to characterize the internal distribution of Ca and Mg in the leaves of a vegetable Brassica and to determine the effects of altered exogenous Ca and Mg supply on this distribution. METHODS: Brassica rapa ssp. trilocularis 'R-o-18' was grown at four different Ca:Mg treatments for 21 d in a controlled environment. Concentrations of Ca and Mg were determined in fully expanded leaves using inductively coupled plasma-mass spectrometry (ICP-MS). Internal distributions of Ca and Mg were determined in transverse leaf sections at the base and apex of leaves using energy-dispersive X-ray spectroscopy (EDS) with cryo-scanning electron microscopy (cryo-SEM). KEY RESULTS: Leaf Ca and Mg concentrations were greatest in palisade and spongy mesophyll cells, respectively, although this was dependent on exogenous supply. Calcium accumulation in palisade mesophyll cells was enhanced slightly under high Mg supply; in contrast, Mg accumulation in spongy mesophyll cells was not affected by Ca supply. CONCLUSIONS: The results are consistent with Arabidopsis thaliana and other Brassicaceae, providing phenotypic evidence that conserved mechanisms regulate leaf Ca and Mg distribution at a cellular scale. The future study of Arabidopsis gene orthologues in mutants of this reference B. rapa genotype will improve our understanding of Ca and Mg homeostasis in plants and may provide a model-to-crop translation pathway for targeted breeding.
BACKGROUND AND AIMS: Leafy vegetable Brassica crops are an important source of dietary calcium (Ca) and magnesium (Mg) and represent potential targets for increasing leaf Ca and Mg concentrations through agronomy or breeding. Although the internal distribution of Ca and Mg within leaves affects the accumulation of these elements, such data are not available for Brassica. The aim of this study was to characterize the internal distribution of Ca and Mg in the leaves of a vegetable Brassica and to determine the effects of altered exogenous Ca and Mg supply on this distribution. METHODS:Brassica rapa ssp. trilocularis 'R-o-18' was grown at four different Ca:Mg treatments for 21 d in a controlled environment. Concentrations of Ca and Mg were determined in fully expanded leaves using inductively coupled plasma-mass spectrometry (ICP-MS). Internal distributions of Ca and Mg were determined in transverse leaf sections at the base and apex of leaves using energy-dispersive X-ray spectroscopy (EDS) with cryo-scanning electron microscopy (cryo-SEM). KEY RESULTS: Leaf Ca and Mg concentrations were greatest in palisade and spongy mesophyll cells, respectively, although this was dependent on exogenous supply. Calcium accumulation in palisade mesophyll cells was enhanced slightly under high Mg supply; in contrast, Mg accumulation in spongy mesophyll cells was not affected by Ca supply. CONCLUSIONS: The results are consistent with Arabidopsis thaliana and other Brassicaceae, providing phenotypic evidence that conserved mechanisms regulate leaf Ca and Mg distribution at a cellular scale. The future study of Arabidopsis gene orthologues in mutants of this reference B. rapa genotype will improve our understanding of Ca and Mg homeostasis in plants and may provide a model-to-crop translation pathway for targeted breeding.
Authors: Simon J Conn; Vanessa Conn; Stephen D Tyerman; Brent N Kaiser; Roger A Leigh; Matthew Gilliham Journal: New Phytol Date: 2011-01-24 Impact factor: 10.151
Authors: Martin R Broadley; John P Hammond; Graham J King; Dave Astley; Helen C Bowen; Mark C Meacham; Andrew Mead; David A C Pink; Graham R Teakle; Rory M Hayden; William P Spracklen; Philip J White Journal: Plant Physiol Date: 2008-02-15 Impact factor: 8.340
Authors: Seosamh Ó Lochlainn; Stephen Amoah; Neil S Graham; Khalid Alamer; Juan J Rios; Smita Kurup; Andrew Stoute; John P Hammond; Lars Østergaard; Graham J King; Phillip J White; Martin R Broadley Journal: Plant Methods Date: 2011-12-08 Impact factor: 4.993
Authors: Thomas D Alcock; Lenka Havlickova; Zhesi He; Ian Bancroft; Philip J White; Martin R Broadley; Neil S Graham Journal: Front Plant Sci Date: 2017-11-15 Impact factor: 5.753
Authors: Neil S Graham; John P Hammond; Artem Lysenko; Sean Mayes; Seosamh O Lochlainn; Bego Blasco; Helen C Bowen; Chris J Rawlings; Juan J Rios; Susan Welham; Pierre W C Carion; Lionel X Dupuy; Graham J King; Philip J White; Martin R Broadley Journal: Plant Cell Date: 2014-07-31 Impact factor: 11.277
Authors: Kaixiong Xing; Mingfei Zhao; Ülo Niinemets; Shuli Niu; Jing Tian; Yuan Jiang; Han Y H Chen; Philip J White; Dali Guo; Zeqing Ma Journal: Front Plant Sci Date: 2021-06-11 Impact factor: 5.753