Ten grape rootstocks were subjected to moisture and salinity stress in two separate experiments. The influence of these stresses on gas exchange, water relation, and biochemical parameters was monitored at various stages of stress cycle. Both stresses indicated significant changes in the physiological and biochemical parameters studied. Some biochemical constituents increased by several folds in few rootstock cultivars which also recorded increased osmotic potential suggesting their role in osmotic adjustment. Some of the rootstock cultivars such as 110R, 1103P, 99R, Dogridge, and B2/56 recorded increased phenolic compounds under stressed conditions. The same rootstock also recorded increased water use efficiency. The increased accumulation of phenolic compounds in these cultivars may indicate the possible role of phenolic compounds as antioxidants for scavenging the reactive oxygen species generated during abiotic stresses thus maintaining normal physiological and biochemical process in leaves of resistant cultivars. 1. Introduction Water scarcity and soli salinity are the major hurdles for grape cultivation as the majority of the area under grape cultivation is concentrated in the semiarid tropical climate of India. The combined effect of these two abiotic stresses in these regions contributed to a decline in the productivity of own-rooted vineyards. Hence, interest in grape rootstocks has intensified, owing to the problems of salinity and drought. Over dependence on a single rootstock Dogridge necessitated the growers to use other rootstocks as some rootstocks cannot perform well under all soil and climatic conditions. Rootstocks are known to influence physiology and biochemical process of the grafted scion varieties as evidenced by several studies. Hence, it is necessary to study the mechanisms by which rootstocks respond to drought and salinity stresses. Rootstocks have been reported to alter the water status and gas exchange parameters of scion varieties in both potted [1] and field conditions [2]. The most important mechanism is that rootstocks genotypes have a major influence on root density [3] although the distribution of grapevine roots is significantly dependent on both soil characteristics and vine spacing. Salt stress in higher plants is regulated by a number of physiological and biochemical processes. High level of salt causes an imbalance of cellular ions resulting in both ion toxicity and osmotic stress causing a production of active O2 species (AOS) as superoxide, hydrogen peroxides, and hydroxyl radicals [4]. To reduce AOS induced
References
[1]
J. Satisha, G. S. Prakash, R. M. Bhatt, and P. Sampath Kumar, “Physiological mechanisms of water use efficiency in grape rootstocks under drought conditions,” International Journal of Agricultural Research, vol. 2, no. 2, pp. 159–164, 2007.
[2]
M. C. Candolfi-Vasconcelos, W. Koblet, G. S. Howell, and W. Zweifel, “Influence of defoliation, rootstock, training system, and leaf position on gas exchange of Pinot noir grapevines,” American Journal of Enology and Viticulture, vol. 45, no. 2, pp. 173–180, 1994.
[3]
L. E. Williams and R. J. Smith, “The effect of rootstocks on the partitioning of dry weight, nitrogen, potassium and root distribution of Cabernet Sauvignon grapevine,” American Journal of Enology and Viticulture, vol. 42, pp. 118–122, 1991.
[4]
M. Ashraf and P. J. C. Harris, “Potential biochemical indicators of salinity tolerance in plants,” Plant Science, vol. 166, no. 1, pp. 3–16, 2004.
[5]
M. M. Posmyk, R. Kontek, and K. M. Janas, “Antioxidant enzymes activity and phenolic compounds content in red cabbage seedlings exposed to copper stress,” Ecotoxicology and Environmental Safety, vol. 72, no. 2, pp. 596–602, 2009.
[6]
Y. Wang and N. Nii, “Changes in chlorophyll, ribulose bisphosphate carboxylase-oxygenase, glycine betaine content, photosynthesis and transpiration in Amaranthus tricolor leaves during salt stress,” Journal of Horticultural Science and Biotechnology, vol. 75, no. 6, pp. 623–627, 2000.
[7]
J. Bota, J. Flexas, and H. Medrano, “Genetic variability of photosynthesis and water use in Balearic grapevine cultivars,” Annals of Applied Biology, vol. 138, no. 3, pp. 353–361, 2001.
[8]
H. D. Barrs and P. E. Weatherly, “A re-examination of the relative turgidity techniques for estimating water deficits in leaves,” Australian Journal of Biological Sciences, vol. 15, pp. 413–428, 1962.
[9]
V. L. Singleton and J. A. Rossi, “Colorimetry of total phenolic with phosphomolybdic phosphotungstic acid reagents,” American Journal of Enology and Viticulture, vol. 16, pp. 144–158, 1965.
[10]
J. M. Dawson and P. L. Heatlie, “Lowry method of protein quantification: evidence for photosensitivity,” Analytical Biochemistry, vol. 140, no. 2, pp. 391–393, 1984.
[11]
H. During and P. R. Dry, “Osmoregulation in water stressed roots: responses of leaf conductance and photosynthesis,” Vitis, vol. 34, no. 1, pp. 15–17, 1995.
[12]
H. R. Schultz, “Physiological mechanisms of water use efficiency in grapevines under drought conditions,” Acta Horticulturae, vol. 526, pp. 115–136, 2000.
[13]
M. L. Rodrigues, M. M. Chaves, M. Wendler et al., “Osmotic adjustment in water stressed grapevines in relation to carbon assimilation,” Australian Journal of Plant Physiology, vol. 20, pp. 309–321, 1993.
[14]
S. Nagarajah, “Physiological response of grape vines to water stress,” Acta Horticulturae, vol. 240, pp. 249–256, 1989.
[15]
A. Patakas and B. Noitsakis, “Mechanisms involved in diurnal changes of osmotic potential in grapevines under drought conditions,” Journal of Plant Physiology, vol. 154, no. 5-6, pp. 767–774, 1999.
[16]
H. Zhongqun, T. Haoru, L. Huanxium, H. Chaoxing, Z. Zhibin, and W. Hauisang, “Arbuscualr Mycorrhizal alleviated ion toxicity, oxidative damage and enhanced osmotic adjustment in tomato subjected to NaCl stress,” American, vol. 7, pp. 676–683, 2010.
[17]
A. G. Reynolds and A. P. Naylor, “‘Pinot noir’ and ‘Riesling’ grapevines respond to water stress duration and soil water-holding capacity,” HortScience, vol. 29, no. 12, pp. 1505–1510, 1994.
[18]
A. N. Lakso, “The effect of water stress on physiological processes in fruit crops,” Acta Horticulturae, vol. 171, pp. 275–290, 1985.
[19]
M. H. Behboudian, R. R. Walker, and E. T？r？kfalvy, “Effects of water stress and salinity on photosynthesis of pistachio,” Scientia Horticulturae, vol. 29, no. 3, pp. 251–261, 1986.
[20]
M. M. Chaves, T. P. Santos, C. R. Souza et al., “Deficit irrigation in grapevine improves water-use efficiency while controlling vigour and production quality,” Annals of Applied Biology, vol. 150, no. 2, pp. 237–252, 2007.
[21]
U. Shani and L. M. Dudley, “Field studies of crop response to water and salt stress,” Soil Science Society of America Journal, vol. 65, no. 5, pp. 1522–1528, 2001.
[22]
J. M. Morgan, “Osmoregulation and water stress in higher plants,” Annual Review of Plant Physiology, vol. 33, pp. 299–319, 1984.
[23]
H. Greenway and R. Munns, “Mechanisms of salt tolerance in non-halophytes,” Annual Review of Plant Physiology, vol. 31, pp. 149–190, 1980.
[24]
C. A. Rice-Evans, N. J. Miller, and G. Paganga, “Antioxidant properties of phenolic compounds,” Trends in Plant Science, vol. 2, no. 4, pp. 152–159, 1997.
[25]
A. K. Parida, A. B. Das, Y. Sanada, and P. Mohanty, “Effects of salinity on biochemical components of the mangrove, Aegiceras corniculatum,” Aquatic Botany, vol. 80, no. 2, pp. 77–87, 2004.
[26]
R. Dostanova, L. K. Klysheve, and K. A. Toibaeva, “Phenol compounds of pea roots under salinization of the medium,” Fiziologiya-i-Biokhimiya Kul’turnykh Rastenii, vol. 11, pp. 40–47, 1979.
[27]
V. M. Latha, V. N. Satakopan, and H. Jayasree, “Salinity induced changes in phenol and ascorbic acid content in groundnut (Arachis hypogaea) leaves,” Current Science, vol. 58, pp. 151–152, 1989.
[28]
J. Matysik, A. Alia, B. Bhalu, and P. Mohanty, “Molecular mechanisms of quenching of reactive oxygen species by proline under stress in plants,” Current Science, vol. 82, no. 5, pp. 525–532, 2002.
[29]
N. Jangpromma, S. Kitthaisong, S. Dadung, P. Jaisil, and S. Thammasirirak, “18KDa protein accumulation in sugarcane leaves under drought stress conditions,” KMITL Science Technology Journal, vol. 7, pp. 44–54, 2007.
[30]
I. Kerepesi and G. Galiba, “Osmotic and salt stress-induced alteration in soluble carbohydrate content in wheat seedlings,” Crop Science, vol. 40, no. 2, pp. 482–487, 2000.
[31]
S. Hajihashemi, K. Kiarostami, S. Enteshari, and A. Saboora, “The effects of salt stress and paclobutrazol on some physiological parameters of two salt-tolerant and salt-sensitive cultivars of wheat,” Pakistan Journal of Biological Sciences, vol. 9, no. 7, pp. 1370–1374, 2006.
