Current Research
Global food security is one of the biggest challenges facing world agriculture. Significant improvements in crop yields are urgently required to meet the 50% increase in world population by 2050. Root architecture impacts the efficient uptake of nutrients, minerals and water from the soil. A greater understanding of the molecular and cellular mechanisms that control root architectural traits like root hair development (Bhosale et al Nature Communications 2018; Giri et al Nature Communications, 2018), lateral root development (Swarup et al 2008, Nature cell Biology, 10, 946-954) and root gravitropism (Swarup et al Science, 2006; Swarup et al Nature Cell Biology 2005) are likely to identify key regulators that may provide the tools to design novel strategies for future crop improvement programmes.
There are three major themes in my lab.
A. BIOSTIMULANTS
One of the key areas of research in my lab is root development and its impact on above ground physiology. I am currently leading a BBSRC-LINK grant investigating the role of phosphite-a plant biostimulant- in promoting plant development. Working with several industrial partners, my group has shown that foliar application of phosphite based formulations consistently enhances root growth and development in a range of crops (Rossall et al, 2016, Acta Horticulturae). This can have great implications for enhancing farm yield in a sustainable manner.
Our results show that low doses of phosphite promote root growth and improve resource use efficiency and thus is likely to have a direct impact on farm income leading to improved nutritional, financial and social stability. This facilitates entry to a new area of precision farming where traits may be deliberately manipulated via application of non harmful chemicals.
We recently have created a white paper summarising key findings of this grant: Further information can be accessed using the links below:
WHITE PAPER
BLOG
------------------------------------------------------------------------------------------------------------------------------------------------
B. AUXIN AND AUXIN TRANSPORT
Another key area of research in my lab is auxins. Auxin is a key plant hormone regulating various aspects of plant growth and development. My work has focussed around AUX/LAX gene family that encodes high affinity auxin transporters which facilitate auxin transport. Recently, in collaboration with Malcolm Bennet group, we have shown that auxin influx carriers are required for low Phosphorus mediated root hair elongation response in Arabidopsis and rice (Bhosale et al 2018, Nature communications; Giri et al 2018, Nature Communications).
My work has previously shown that AUX/LAX proteins are located on the plasma membrane (PM). My work on AUX1 provided evidence that AUX1 PM localisation is mediated by AXR4 (Swarup et al Science, 2006). Currently my group is focusing on rice homolog of AXR4. Using genetic and functional complementation approaches, my group has shown that rice AXR4 is a functional homolog of Arabidopsis AXR4 (manuscript under preparation).
Our group has also been investigating molecular mechanisms regulating lateral root development. Auxin is one of the key hromones regulating lateral root development. We have previuosly shown that auxin influx carrier LAX3 plays a key role in lateral root emergence (Swarup et al 2008, Nature Cell Biology).
In recent years we have been involved in very detailed gene expression profiling during lateral root organogenesis and generated data sets for wild type and in the mutant backgrounds of four key regulators of lateral root development (ARF7, ARF19, LBD16 and LBD29). A number of candidate genes are currently been investigated for their role in lateral root development.
--------------------------------------------------------------------------------------------------------------------------------------------
C. SHOOT AND ROOT CROSS TALK
One of the key areas of research in my lab is root and shoot signalling. As a proof of concept study in collaboration with Erik Murchie and Julie Gray (Sheffield University), we have manipulated stomata numbers in rice to reduce water loss and show that this results in improved tolerance to drought (Mohammed et al, 2018, Scientific Report).
------------------------------------------------------------------------------------------------------------------------------------------------Selected Publications
Swarup R and Bhosale R (2019) Developmental roles of AUX1/LAX auxin Influx carriers in plants. Frontiers in Plant Science, 10:1306.
Swarup R and Denyer T (2019) miRNAs in plant development. In: Annual Plant Reviews, Vol 2, J Roberts (ed) John Wiley & Sons, Ltd.
Silva-Navas J, Conesa CM, Saez A, Navarro-Neila S, Garcia-Mina JM, Zamarreño AM, Baigorri R, Swarup R, and Del Pozo JC (2019) Role of cis-zeatin in root responses to phosphate starvation. New Phytologist doi: 10.1111/nph.160202019.
Mohammed U, Caine RS, Atkinson JA, Wells D, Chater CC, Gray JE, Swarup R, Murchie EH (2019) Rice plants overexpressing OsEPF2 show reduced stomatal density and increased root cortical aerenchyma formation. Scientific Report (Nature) 9:5584.
Caine RS, Sloan J, Harrison EL, Mohammed U, Fulton T, Biswal AK, Dionora J, Chater CC, Coe RA, Bandyopadhyay A, Murchie E, Swarup R, Quick P and Gray JE (2018) Rice with reduced stomatal density conserves water and has improved drought tolerance under future climate conditions. New Phytologist, 221, 371-384.
Bhosale R, Giri J, Pandey BK, Giehl RFH, Hartmann A, Traini R, Truskina J, Leftley N, Hanlon M, Swarup K, Rashed A, Voß U, Alonso J, Stepanova A, Yun J, Ljung K, Brown KM, Lynch JP, Dolan L, Vernoux T, Bishopp A, Wells D, von Wirén N, Bennett MJ and Swarup R (2018) A mechanistic framework for auxin dependent Arabidopsis root hair elongation to low external phosphate. Nature Communications 9, 1409.
Giri J, Bhosale R, Huang G, Pandey BK, Parker H, Zappala S, Yang J, Dievart A, Bureau C, Ljung K, Price A, Rose T, Larrieu A, Mairhofer S, Sturrock CJ, White P, Dupuy L, Hawkesford M, Perin C, Liang W, Peret B, Hodgman CT, Lynch J, Wissuwa M, Zhang D, Pridmore T, Mooney SJ, Guiderdoni E, Swarup R and Bennett MJ (2018) Rice auxin influx carrier OsAUX1 facilitates root hair elongation in response to low external phosphate. Nature Communications 9, 1408.
Muller L, Bennett MJ, French A, Wells DM and Swarup R (2018) Root Gravitropism: Quantification, Challenges and Solutions. Methods in Molecular Biology, 1761, 103-112.
Rossall S, Qing C, Paneri M, Bennett M and Swarup R (2016) A 'growing' role for phosphites in promoting plant growth and development. Acta Hortic 1148, 61-67.
Swarup R, Crespi M and Bennett M (2016) One gene, many proteins: Mapping cell-specific alternative splicing in plants. Dev Cell, 39, 383-385.
Sato EM, Hijazi H, Bennett MJ, Vissenberg K, Swarup R (2015) New insights into root gravitropic signalling. J Exp Bot, 66, 2155-2165.
Swarup R and Bennett MJ (2014) Auxin Transport: Providing plants with a new sense of direction. Biochemist 36, 12-16.
Boutté Y, Jonsson K, McFarlane H, Johnson E, Gendre D, Swarup R, Friml J, Samuels J, Robert S and Bhalerao R (2013) ECHIDNA-mediated post-Golgi trafficking of auxin carriers for differential cell elongation. Proc Natl Acad Sci, USA, 110, 16259-16264.
Peret B, Yang Y, Swarup K, James N, Ferguson A, Casimiro I, Perry P, Syed A, Laplaze L, Bennett M, Murphy A, Nielsen E and Swarup R (2012) AUX/LAX genes encode a family of auxin influx transporters that perform distinct function during Arabidopsis development. Plant Cell, 24, 2874-2885.
Swarup R, Swarup K, Benková E, Casimiro I, Péret B, Yang Y, Parry G, et al (2008) The auxin influx carrier LAX3 promotes lateral root emergence. Nature Cell Biol, 10, 946-954.
Swarup R, Dharmasiri S, Mockaitis K, Dharmasiri N, Singh S, Kowalchyk A, Marchant A, Mills S, Sandberg G, Bennett M and Estelle M (2006) AXR4 is required for localisation of AUX1. Science, 312, 1218-1220.
Swarup R, Kramer E, Perry P, Knox K, Leyser HMO, Haseloff J, Beemster G, Bhalerao R and Bennett M (2005) Root gravitropism requires lateral root cap and epidermal cells for transport and response to a mobile auxin signal. Nature Cell Biol, 7, 1057-1065.
Swarup R, Kargul J, Marchant A, Zadik D, Rahman A, Mills R, Yemm A, May S, Williams L, Millner P, Tsurumi S, Moore I, Napier R, Kerr ID and Bennett MJ 2004 Structure-Function Analysis of the presumptive Arabidopsis Auxin Permease AUX1. Plant Cell, 14, 3069-3083.
Swarup R and Bennett MJ (2003) Auxin transport: the fountain of life in plants? Dev Cell, 5, 1-2.
Swarup R, Parry G, Graham N, Allen T and Bennett M J (2002) Auxin cross-talk: integration of signalling pathways to control plant development. Plant Mol Biol, 49, 411-426.
Swarup R, Friml J, Marchant A, Ljung K, Sandberg G, Palme K and Bennett MJ (2001) Localization of the auxin permease AUX1 suggests two functionally distinct hormone transport pathways operate in the Arabidopsis root apex. Genes Dev, 15, 2648-2653.
Past Research
Plant hormone auxin is crucial for plant growth and development. We mapped the tissues required for auxin transport and auxin response during root gravitropism (Swarup et al, 2005, Nature Cell Biology, 7, 1057-1065). This study revealed that epidermis is the primary site for auxin action during root gravitropism.