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Influence of environmental stress on biomass partitioning in transgenic tobacco plants expressing the movement protein of tobacco mosaic virus
- Balachandran, S., Hull, R.J., Martins, R.A., Vaadia, Y., Lucas, W.J.
- Plant physiology 1997 v.114 no.2 pp. 475-481
- Nicotiana tabacum, transgenic plants, gene expression, genetic vectors, Tobacco mosaic virus, viral proteins, nutrient transport, roots, shoots, water stress, nutrient deficiencies, nitrogen, potassium, phosphorus, source-sink relationships, genetic variation, translocation (plant physiology), genotype, photosynthates, stress response
- The influence of various environmental factors on biomass partitioning between shoots and roots in transgenic tobacco (Nicotiana tabacum) plants expressing the movement protein (MP) of tobacco mosaic virus (TMV) was investigated. TMV-MP-expressing transgenic plants exhibited a root-to-shoot ratio that was approximately 40% below that of transgenic vector control plants. When transgenic plants expressing the TMV-MP were subjected to water-stress conditions, the root-to-shoot ratio was increased to a value comparable to that of control plants subjected to the same water-stress treatment. Although the root-to-shoot ratio was increased by N or P deficiencies, the TMV-MP-induced alteration in biomass partitioning was not overcome. Surprisingly, under K+-deficient growth conditions, both TMV-MP-expressing and control plants exhibited reduced root-to-shoot ratios when compared with plants grown in the presence of sufficient K+. Furthermore, plant growth under K+-deficient conditions did not alleviate the influence of the TMV-MP over resource allocation to the roots. These results are discussed in terms of possible mechanisms by which stress signals could cause an alteration in biomass partitioning between shoots and roots in control and transgenic tobacco plants expressing the TMV-MP.