Drought and Salt Tolerance

Agricultural productivity is severely af fected by water availability, and the damaging effects of water stress have influenced ancient and modern civilizations. 

The need to produce stress-tolerant crops was evident even in ancient periods 

Two basic genetic approaches are currently being utifized to improve stress tolerance  

we discuss these approaches and focus on the recent experimentation with transgenic plants that has led to increased sahnity and drought tolerance. 

Tomato has been a valuable species to analyze the genetic basis of salinity and drought tolerance, because making successful crosses between wild and cultivated tomato plants are relatively simple. Lyon 

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Lauchli A., Grattan SR. Plant growth and development under salinity stress. Jenks MA, Hasegawa PM. Jain SM. (ed.) Advances in Molecular Breeding toward Drought and Salt Tolerant Crops. Dordrecht, Netherlands, Springer 2007,1-32. 

Sohn, K.H., S.C. Lee, H.W. Jung, J.K. Hong, and B.K. Hwang. 2006. Expression and functional roles of the pepper pathogen-induced transcription factor RAV1 in bacterial disease resistance and drought and salt tolerance. Plant Mol. Biol. 61 897-915. 

Set out in spring or fall as bare-root or balled-and-burlapped plants. Honey locusts are undemanding and are well-suited to city conditions. While they prefer moist, fertile, slightly alkaline soil, they tolerate drought and salt. 

As stated earlier, mycorrhizae enhance nutrient absorption. Greater soil exploitation by mycorrhizal roots as a means of increasing phosphate uptake is well established. The normal phosphate depletion zone around non-mycorrhizal roots is 1-2 mm, but an endomycorrhizal root symbiont increased this zone to 7 cm (140). This ability to increase the nutritional level (particularly with regard to phosphorus), and subsequently the overall better growth dynamics of the mycorrhizal plant has been suggested as the reason for the salt (43) and drought (44-46) tolerance and increased nodulation (47) observed in mycorrhizal associations. Another interesting aspect of this enhanced nutrient uptake is the possible effect of mycorrhizae on competitive ability between two plant species. Under some conditions, mycorrhizal... 

Expression of ERF3 and ERF4 from sugarcane and cotton, respectively, rapidly increases response to exogenous ethylene and ABA, salt, cold, and drought, whereas their overexpression in transgenic plants enhances tolerance to drought and osmotic stress. ... 

Above experiments indicated that protection of photosynthesis under salt/drought stress would be suitable target for the Improvement of plant productivity. Previously, we selected high NaCl-adapted photoautotrophic tobacco cells and characterized their characteristics of salt-tolerance (Sato et al., 1992 Murota et al., 1994). Our characterization indicated that photosynthetic activity of photosystem II (PSII),... 

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