Root growth of somatic plants of hybrid Pinus strobus (L.) and P. wallichiana (A. B. Jacks.) is affected by the nitrogen composition of the somatic embryo germination medium
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This paper describes improvement in root growth of hybrid white pine somatic plants on a somatic embryo germination medium containing solely organic nitrogen sources.
Mature somatic embryos of F2 hybrid Pinus strobus × Pinus wallichiana backcrossed with P. strobus converted to plants but survival of the somatic plants was not satisfactory prompting the present study on somatic seedling root growth on germination media varying in nitrogen (N) composition. The media were modifications of Litvay’s (Litvay et al. in Plant Cell Rep 4:325–328, 1985) which included two main groups: G1, G2, G3, G4 all contained inorganic N with or without glutamine (Gln) or casein hydrolysate (CH) and G5, G6, G7 contained solely glutamine and/or CH. In addition, G8 was half-strength G1 (with organic N) and G9 was half-strength CD (Campbell and Durzan in Can J Bot 53:1652–1657, 1975) without organic N. The roots of plants growing on media containing solely organic N grew about 2.55 times longer than on those containing solely inorganic N or both inorganic and organic N. The longest roots grew on G7 supplemented with CH and on G5 with both CH and Gln. Microarray analysis of somatic plants germinated on G1 versus G7 revealed that depending on the N source the somatic plants displayed changes in the transcriptome resulting in the differential expression of a range of genes involved in essential processes for plant growth and development. Roots grown in the absence of inorganic N were capable of rapid uptake of labelled inorganic 15N during the 2 h incubation in the nutrient solution. The somatic plants from G5 medium acclimatized at the rate twice as high as those from G1 (with both inorganic and organic N) and G2 (solely inorganic N) under standard fertilization regime.
KeywordsEastern white pine Himalayan pine 15N uptake Root length Somatic embryogenesis Microarrays
Modified Litvay’s medium
and Durzan medium
White pine blister rust
This work was supported by Grants from the Spanish Ministerio de Economía y Competitividad (BIO2015-69285-R) and Junta de Andalucía (BIO-474) to M.T.L.L. We gratefully acknowledge the assistance of Dr. Javier Canales (University of Malaga) with microarray analysis, Mrs. Cathy Overton with the production of mature somatic embryos and acclimatization of somatic plants and Mrs. Michèle Bernier-Cardou for the statistical analyses (Natural Resources Canada, Canadian Forest Service).
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Conflict of interest
The authors declare that they have no conflict of interest.
- Canales J, Avila C, Cantón FR, Pacheco-Villalobos D, Díaz-Moreno S, Ariza D, Molina-Rueda JJ, Navarro-Cerrillo RM, Gonzalo Claros MG, Cánovas FM (2012a) Gene expression profiling in the stem of young maritime pine trees: detection of ammonium stress-responsive genes in the apex. Trees 26:609–619CrossRefGoogle Scholar
- Daoust G, Klimaszewska K, Plourde D (2009) Somatic embryogenesis, a tool for accelerating the selection and deployment of hybrids of eastern white pine (Pinus strobus) and Himalayan white pine (Pinus wallichiana) resistant to white pine blister rust (Cronartium ribicola). In: Noshad D, Noh EW, King J, Sniezko RA (eds) Breeding and genetic resources of five-needle pines. In: Proceedings of the conference 2008, Yangyang, Korea. Korea Forest Research Institute, Seoul. ISBN:978-89-8176-605-4 (93520)Google Scholar
- Graan T, Ort DR (1984) Quantitation of the rapid electron donors to P700, the functional plastoquinone pool, and the ratio of the photosystems in spinach chloroplasts. J Biol Chem 259:4003–14010Google Scholar
- Van Zyl L, von Arnold S, Chen Y, Egertsdotter U, Mackay J, Sederoff R, Shen J, Zelena L, Clapham DH (2002) Heterologous array analysis in Pinaceae: hybridization of Pinus taeda cDNA arrays with cDNA from needles and embryogenic cultures of P. taeda, P. sylvestris or Picea abies. Comp Funct Genom 3:306–318CrossRefGoogle Scholar
- Westfall P, Tobias RD, Rom D, Wolfinger RD, Hochberg RD (1999) Multiple comparisons and multiple tests using the SAS system. SAS Institute Inc., CaryGoogle Scholar