Root growth plasticity to drought in seedlings of perennial grasses
- 377 Downloads
Root growth strategies may be critical for seeding survival and establishment under dry conditions, but these strategies and their plasticity are little known. We aim to document the ability of young grass seedlings to adjust their root system architecture, root morphology and biomass allocation to roots to promote water uptake and survival under progressive drought.
Seedlings growing in columns filled with sand and exposed to drought or well-watered controls were repeatedly harvested for determination of biomass fractions, root length, −architecture and -morphology in a greenhouse experiment. Allometric scaling exponents and standardised major axis regression were used to investigate allocation patterns.
Young seedlings were able to sustain leaf turgor and functions during eight weeks of progressive drought through phenotypic plasticity of the primary root system producing deeper and simpler roots. Biomass allocation to roots decreased or did not respond, and other components of root morphology showed only moderate plasticity.
Our results suggest that morphological and architectural plasticity of the primary root system may well be key features for dehydration avoidance and survival in grass seedlings under moderate drought when allocation of biomass to roots and development of secondary roots are constrained.
KeywordsAllometry Seedling strategies Rooting depth Root system architecture
This study was funded by The Research Council of Norway, grant no. 208204. The authors have no conflicts of interest to declare.
- Ameztegui A (2017) Plasticity: an R package to determine several plasticity indices. GitHub repository, https://github.com/ameztegui/Plasticity
- Andrade BO, Overbeck GE, Pilger GE, Hermann JM, Conradi T, Boldrini II, Kollmann J (2014) Intraspecific trait variation and allocation strategies of calcareous grassland species: results from a restoration experiment. Basic Appl Ecol 15:590–598. https://doi.org/10.1016/j.baae.2014.08.007 CrossRefGoogle Scholar
- Bi A, Fan J, Hu Z, Wang G, Amombo E, Fu J, Hu T (2016) Differential acclimation of enzymatic antioxidant metabolism and photosystem ii photochemistry in tall fescue under drought and heat and the combined stresses. Front Plant Sci 7:453. https://doi.org/10.3389/fpls.2016.00453 CrossRefPubMedPubMedCentralGoogle Scholar
- Bristiel P, Roumet C, Violle C, Volaire F (2019) Coping with drought: root trait variability within the perennial grass Dactylis glomerata captures a trade-off between dehydration avoidance and dehydration tolerance. Plant Soil 434:327–342. https://doi.org/10.1007/s11104-018-3854-8 CrossRefGoogle Scholar
- Cornelissen JHC, Lavorel S, Garnier E, Díaz S, Buchmann N, Gurvich DE, Reich PB, ter Steege H, Morgan HD, van der Heijden MGA, Pausas JG, Poorter H (2003) A handbook of protocols for standardised and easy measurement of plant functional traits worldwide. Aust J Bot 51:335–380. https://doi.org/10.1071/BT02124 CrossRefGoogle Scholar
- Falster DS, Warton DI, Wright IJ (2006) SMATR: standardised major axis tests and routines, ver 2.0. http://www.bio.mq.edu.au/ecology/SMATR/
- Fitter A (2002) Characteristics and functions of root systems. Plant Roots: The Hidden Half, Third Edition, (eds Y. Waisel, A. Eshel, T. Beeckman & U. Kafkafi), pp 21–50. CRC PressGoogle Scholar
- Funk JL, Larson JE, Ames G, Butterfield B, Cavender-Bares J, Firn J, Laughlin DC, Sutton-Grier A, Williams L, Wright J (2017) Revisiting the holy grail: using plant functional traits to understand ecological processes. Biol Rev 92:1156–1173. https://doi.org/10.1111/brv.12275 CrossRefPubMedGoogle Scholar
- Gaviria J, Engelbrecht BMJ (2015) Effects of drought, pest pressure and light availability on seedling establishment and growth: their role for distribution of tree species across a tropical rainfall gradient. PLoS One 10:e0143955. https://doi.org/10.1371/journal.pone.0143955 CrossRefPubMedPubMedCentralGoogle Scholar
- Gonzalez-Dugo V, Durand JL, Gastal F, Bariac T, Poincheval J, Bardou G, Biron P, Cousson L, Eprinchard A, Millet G, Richard P, Terrasson J-P (2012) Restricted root-to-shoot translocation and decreased sink size are responsible for limited nitrogen uptake in three grass species under water deficit. Environ Exp Bot 75:258–267. https://doi.org/10.1016/j.envexpbot.2011.07.009 CrossRefGoogle Scholar
- Granier C, Aguirrezabal L, Chenu K, Cookson SJ, Dauzat M, Hamard P, Thioux JJ, Rolland G, Bouchier-Combaud S, Lebaudy A, Muller B, Simonneau T, Tardieu F (2006) PHENOPSIS, an automated platform for reproducible phenotyping of plant responses to soil water deficit in Arabidopsis thaliana permitted the identification of an accession with low sensitivity to soil water deficit. New Phytol 169:623–635. https://doi.org/10.1111/j.1469-8137.2005.01609.x CrossRefPubMedGoogle Scholar
- Harada J, Yamazaki K (1993) Roots. Science of the Rice Plant, Volume 1, Morphology. (eds T. Matsuo, K. Hoshikawa), pp 133–186. Food and Agriculture Policy Research Centre, TokyoGoogle Scholar
- Hoekstra NJ, Finn JA, Hofer D, Lüscher A (2014) The effect of drought and interspecific interactions on depth of water uptake in deep- and shallow-rooting grassland species as determined by δ18O natural abundance. Biogeosciences 11:4493–4506. https://doi.org/10.5194/bg-11-4493-2014 CrossRefGoogle Scholar
- Jupp AP, Newman EI (1987) Morphological and anatomical effects of severe drought on the roots of Lolium perenne L. New Phytol 105:393–402. https://doi.org/10.1111/j.1469-8137.1987.tb00876.x CrossRefGoogle Scholar
- Kitajima K, Myers JA (2008) Seedling ecophysiology:strategies toward achievement of positive net carbon balance. Seedling Ecology and Evolution (eds M.A. Leck, T. Parker & R.L. Simpson), pp. 172–188. Cambridge University Press. https://doi.org/10.1017/CBO9780511815133.010
- Liu ZM, Thompson K, Spencer R, Reader RJ (2000) A comparative study of morphological responses of seedling roots to drying soil in 20 species from different habitats. Acta Bot Sin 42:628–635Google Scholar
- Lloret F, Peñuelas J, Estiarte M (2005) Effects of vegetation canopy and climate on seedling establishment in Mediterranean shrubland. J Veg Sci 16:67–76. https://doi.org/10.1111/j.1654-1103.2005.tb02339.x CrossRefGoogle Scholar
- Ludlow MM (1989) Strategies of response to water stress. In: Kreeb KH, Richter H, Hinckley TM (eds) Structural and functional responses to environmental stresses: water shortage. SPB Academic Publishing BV, The Hague, pp 269–281Google Scholar
- R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL http://www.R-project.org/
- Raiche G, Magis D (2015) nFactors: parallel analysis and non graphical solutions to the Cattell scree test. R package Version 2.3.3Google Scholar
- Ramírez-Valiente J-A, Aranda I, Sanchéz-Gómez D, Rodríguez-Calcerrada J, Valladares F, Robson TM (2019) Increased root investment can explain the higher survival of seedlings of ‘Mesic’ Quercus suber than ‘xeric’ Quercus ilex in sandy soils during a summer drought. Tree Physiol 39:64–75. https://doi.org/10.1093/treephys/tpy084 CrossRefPubMedGoogle Scholar
- Rosas U, Cibrian-Jaramillo A, Ristova D, Banta JA, Gifford ML, Fan AH, Zhou RW, Kim GJ, Krouk G, Birnbaum KD, Purugganan MD, Coruzzi GM (2013) Integration of responses within and across Arabidopsis natural accessions uncovers loci controlling root systems architecture. P Natl Acad Sci USA 110:15133–15138. https://doi.org/10.1073/pnas.1305883110 CrossRefGoogle Scholar
- Wilson AM, Hyder DN, Briske DD (1976) Drought resistance characteristics of blue grama seedlings. Agron J 68:479–484. https://doi.org/10.2134/agronj1976.00021962006800030012x CrossRefGoogle Scholar
- Yang H-L, Zhu X-W, Dong M, Huang Z-Y, Cao Z-P (2005) Responses of caryopsis germination, seedling emergence, and development to sand water content of Agropyron cristatum (L.) Gaertn. And Bromus inermis Leyss. J Integr Plant Biol 47:1450–1458. https://doi.org/10.1111/j.1744-7909.2005.00170.x CrossRefGoogle Scholar