Genetic and physiological analysis of early drought response in Manihot esculenta and its wild relative
Cassava (Manihot esculenta) is a staple food crop mostly grown in the tropics. Successful cultivation in marginal areas derives from its ability to withstand difficult environmental conditions. Aiming at providing new insights into drought tolerance in Manihot spp., we performed physiological and molecular analyses of early drought response in three cassava varieties and in the wild species, Manihot glaziovii (maniçoba). Plants grown in pots were subjected to three water regimes for 5 days, based on soil field capacity (FC): 75% (well-watered plants); 45% (moderately stressed plants), and 20% (severely stressed plants), under greenhouse condition. Analysis of leaf gas exchange showed a downward trend in photosynthesis, stomatal conductance, and transpiration, with intensification of the stress, in all genotypes, being significantly reduced only at 20% FC. Maniçoba stood out for maintaining a positive carbon balance in severe stress condition via stomatal aperture control. Photoinhibition of the photosystem II by drought was also evident only at 20% FC. There was no clear association between proline accumulation and drought stress tolerance. Expression analysis of nine genes encoding heat-shock proteins, transcription factors, a cell redox homeostasis protein, and a no-hit protein confirmed the activation of classical stress-responsive pathways, especially those involved in oxidative damage avoidance. These results reinforce the intrinsic drought tolerance of cassava, highlight the superior performance of maniçoba under water deficit conditions, and give insights into drought phenotyping in cassava and contribute to further development of functional molecular markers to be used in assisted breeding.
KeywordsCassava Manihot glaziovii Water deficit Gene expression analysis RT-qPCR
The authors thank the Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the financial assistance and scholarship support.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Aglawe SB, Fakrudin B, Patole CB et al (2012) Quantitative RT-PCR analysis of 20 transcription factor genes of MADS, ARF, HAP2, MBF and HB families in moisture stressed shoot and root tissues of sorghum. Physiol Mol Biol Plants 18:287–300. https://doi.org/10.1007/s12298-012-0135-5 CrossRefPubMedPubMedCentralGoogle Scholar
- Alves AAC, Setter TL (2004) Abscisic acid accumulation and osmotic adjustment in cassava under water deficit. Environ Exp Bot 51:259–271. https://doi.org/10.1007/s12298-012-0135-510.1016/j.envexpbot.2003.11.005 CrossRefGoogle Scholar
- Beltrán J, Jaimes H, Echeverry M et al (2009) Quantitative analysis of transgenes in cassava plants using real-time PCR technology. Vitr Cell Dev Biol - Plant 45:48–56. https://doi.org/10.1007/s12298-012-0135-510.1007/s11627-008-9159-5 CrossRefGoogle Scholar
- Betti M, Pérez-Delgado C, García-Calderón M et al (2012) Cellular stress following water deprivation in the model legume Lotus japonicus. Cells 1:1089–1106. https://doi.org/10.1007/s12298-012-0135-510.3390/cells1041089 CrossRefPubMedPubMedCentralGoogle Scholar
- Calatayud P-A, Llovera E, Bois JF, Lamaze T (2000) Photosynthesis in drought-adapted Cassava. Photosynthetica 38:97–104. https://doi.org/10.1007/s12298-012-0135-510.1023/A:1026704226276 CrossRefGoogle Scholar
- de Oliveira EJ, de Aidar S, Morgante CV et al (2015) Genetic parameters for drought-tolerance in cassava. Pesqui Agropecu Bras 50:233–241. https://doi.org/10.1007/s12298-012-0135-510.1590/S0100-204X2015000300007 CrossRefGoogle Scholar
- de Oliveira EJ, Morgante CV, de Tarso AS et al (2017) Evaluation of cassava germplasm for drought tolerance under field conditions. Euphytica 213:188. https://doi.org/10.1007/s12298-012-0135-510.1007/s10681-017-1972-7 CrossRefGoogle Scholar
- de Souza AP, Massenburg LN, Jaiswal D et al (2017) Rooting for cassava: insights into photosynthesis and associated physiology as a route to improve yield potential. New Phytol 213:50–65. https://doi.org/10.1007/s12298-012-0135-510.1111/nph.14250 CrossRefPubMedGoogle Scholar
- FAO (2014) Faostat—Food and Agriculture Organization of the United Nations statistics databaseGoogle Scholar
- Ferreira EB, Cavalcanti, PP, Nogueira DA (2018) ExPDes: Experimental Design. R Package version 1.2.0. https://cran.r-project.org/web/packages/ExpDes. Accessed 21 May 2018
- Mendiburu F (2019) Agricolae: Statistical Procedures for Agricultural Research. R Package version 1.3-1. https://cran.r-project.org/web/packages/agricolae/. Accessed 21 May 2018
- Sakamoto H, Maruyama K, Sakuma Y et al (2004) Arabidopsis Cys2/His2-type zinc-finger proteins function as transcription repressors under drought, cold, and high-salinity stress conditions. Plant Physiol 136:2734–2746. https://doi.org/10.1104/pp.104.046599.2734 CrossRefPubMedPubMedCentralGoogle Scholar
- Sundaresan S, Sudhakaran PR (1995) Water stress-induced alterations in the proline metabolism of drought-susceptible and -tolerant cassava (Manihot esculenta) cultivars. Physiol Plant 94:635–642. https://doi.org/10.1111/j.1399-3054.1995.tb00978.x CrossRefGoogle Scholar
- Wang B, Guo X, Zhao P et al (2017) Molecular diversity analysis, drought related marker-traits association mapping and discovery of excellent alleles for 100-day old plants by EST-SSRs in cassava germplasms (Manihot esculenta Cranz). PLoS ONE One 12:e0177456. https://doi.org/10.1371/journal.pone.0177456 CrossRefGoogle Scholar