Evaluation of the differential osmotic adjustments between roots and leaves of maize seedlings with single or combined NPK-nutrient supply
Christoph Studer A B , Yuncai Hu A C and Urs Schmidhalter AA Technical University of Munich, D-85350 Freising, Germany.
B Swiss College of Agriculture, CH-3052 Zollikofen, Switzerland.
C Corresponding author. Email: hu@wzw.tum.de
Functional Plant Biology 34(3) 228-236 https://doi.org/10.1071/FP06294
Submitted: 10 November 2006 Accepted: 27 February 2007 Published: 22 March 2007
Abstract
Many physiological mechanisms associated with nutrient supply have been implicated as improving plant growth under drought conditions. However, benefits to plant growth under drought might derive from an increased recovery of soil water through osmotic adjustment in the shoots and especially in the roots. Thus, experiments were carried out to investigate the effects of the nutrients N, P and K applied singly or in combination, on the osmotic adjustment and turgor maintenance in the roots and leaves of maize seedlings. The seedlings were harvested between 18 and 37 days after sowing according to the soil matric threshold potentials. Soil matric potentials and shoot and root biomass were determined at harvest. Turgor pressure and osmotic adjustment of the leaves and roots were estimated by measurements of their water and osmotic potentials. Results showed that plants with either of the combined fertilisation treatments NPK or NP grew faster at a given level of drought stress than those with no fertilisation, N, P or K applied individually or the combined nutrient treatments PK and NK. Among the fertiliser applications with either a single or two combined nutrients, plants treated with any of N, P or NP grew faster than those with either K or NK. The association between the interactive effects of nutrients and drought stress on the osmotic adjustment and turgor maintenance in roots may partially explain the role of nutrients in drought tolerance of maize seedlings. In particular, the roots exhibited a higher osmotic adjustment than the leaves for all nutrient treatments, suggesting that shoot growth shows a higher sensitivity to water deficit compared to root growth. We conclude that the maintained turgor of roots under drought stress obtained with an optimal nutrient supply results in better root growth and apparently promotes overall plant growth, suggesting that osmotic adjustment is an adaptation not only for surviving stress, but also for growth under such conditions.
Additional keywords: maize, nitrogen, osmotic adjustment, phosphorus, potassium, turgor maintenance, water stress.
Acknowledgements
Authors thank Dr N. C. Turner, University Western Australia, School of Plant Biology, Crawley, Australia, for helpful suggestions and critical reading of the manuscript.
Ackerson RC
(1985) Osmoregulation in cotton in response to water stress. 3. Effects of phosphorus fertility. Plant Physiology 77, 309–312.
| PubMed |
Barlow EWR
(1986) Water relations of expanding leaves. Australian Journal of Plant Physiology 13, 45–58.
Bataglia OC,
Quaggio JA,
Brunini O, Ciarelli DM
(1985) Effect of nitrogen-fertilization on osmotic adjustment in maize and sorghum. Pesquisa Agropecuaria Brasileira 20, 659–665.
Bennett JM,
Jones JW,
Zur B, Hammond LC
(1986) Interactive effects of nitrogen and water stresses on water relations of field-grown corn leaves. Agronomy Journal 78, 273–280.
Brueck H,
Payne WA, Sattelmacher B
(2000) Effects of phosphorus and water supply on yield, transpirational water-use efficiency, and carbon isotope discrimination of pearl millet. Crop Science 40, 120–125.
Catsky J,
Velichkov DK,
Pospisilova J,
Solarova J, Ticha I
(1987) Contribution of leaves of different ages to plant carbon balance as affected by potassium supply and water stress. Biologia Plantarum 29, 355–364.
Debaeke P, Aboudrare A
(2004) Adaptation of crop management to water-limited environments. European Journal of Agronomy 21, 433–446.
| Crossref | GoogleScholarGoogle Scholar |
Enns LC,
Canny MJ, McCully ME
(2000) An investigation of the role of solutes in the xylem sap and in the xylem parenchyma as the source of root pressure. Protoplasma 211, 183–197.
| Crossref | GoogleScholarGoogle Scholar |
Greacen EL, Oh JS
(1972) Physics of root growth. Nature: New Biology 235, 24–50.
| PubMed |
Hare PD,
Cress WA, van Staden J
(1998) Dissecting the roles of osmolyte accumulation during stress. Plant, Cell & Environment 21, 535–553.
| Crossref | GoogleScholarGoogle Scholar |
Hsiao TC, Xu LK
(2000) Sensitivity of growth of roots versus leaves to water stress: biophysical analysis and relation to water transport. Journal of Experimental Botany 51, 1595–1616.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Hu YC, Schmidhalter U
(2005) Drought and salinity: a comparison of their effects on mineral nutrition of plants. Journal of Plant Nutrition and Soil 168, 541–549.
| Crossref | GoogleScholarGoogle Scholar |
Kriedemann PE
(1986) Stomatal and photosynthetic limitations to leaf growth. Australian Journal of Plant Physiology 13, 15–31.
Ludlow MM, Muchow RC
(1990) A critical evaluation of traits for improving crop yields in water-limited environments. Advances in Agronomy 43, 107–153.
Matyssek R,
Tang AC, Boyer JS
(1991) Plants can grow on internal water. Plant, Cell & Environment 14, 925–930.
| Crossref | GoogleScholarGoogle Scholar |
McCully ME
(1999) Root xylem embolisms and refilling. Relation to water potentials of soil, roots, and leaves, and osmotic potentials of root xylem sap. Plant Physiology 119, 1001–1008.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Michelena VA, Boyer JS
(1982) Complete turgor maintenance at low water potentials in the elongating region of maize leaves. Plant Physiology 69, 1145–1149.
| PubMed |
Morgan JA
(1986) The effects of N-nutrition on the water relations and gas-exchange characteristics of wheat (Triticum aestivum L.). Plant Physiology 80, 52–58.
| PubMed |
Morgan JM
(1984) Osmoregulation and water-stress in higher plants. Annual Review of Plant Physiology and Plant Molecular Biology 35, 299–319.
| Crossref | GoogleScholarGoogle Scholar |
Morgan JM
(1992) Adaptation to water deficits in 3 grain legume species – mechanisms of turgor maintenance. Field Crops Research 29, 91–106.
| Crossref | GoogleScholarGoogle Scholar |
Morgan JM
(1995) Growth and yield of wheat lines with differing osmoregulative capacity at high soil-water deficit in seasons of varying evaporative demand. Field Crops Research 40, 143–152.
| Crossref | GoogleScholarGoogle Scholar |
Morgan JM, Condon AG
(1986) Water-use, grain-yield, and osmoregulation in wheat. Australian Journal of Plant Physiology 13, 523–532.
Munns R
(1988) Why measure osmotic adjustment? Australian Journal of Plant Physiology 15, 717–726.
Munns R,
Brady CJ, Barlow EWR
(1979) Solute accumulation in the apex and leaves of wheat during water-stress. Australian Journal of Plant Physiology 6, 379–389.
Munns R, Weir R
(1981) Contribution of sugars to osmotic adjustment in elongating and expanded zones of wheat leaves during moderate water deficits at 2 light levels. Australian Journal of Plant Physiology 8, 93–105.
O’Toole JC, Bland WL
(1987) Genotypic variation in crop plant-root systems. Advances in Agronomy 41, 91–145.
Passioura JB
(1991) An impasse in plant water relations. Botanica Acta 104, 405–411.
Premachandra GS,
Saneoka H,
Fujita K, Ogata S
(1990) Cell-membrane stability and leaf water relations as affected by nitrogen nutrition under water-stress in maize. Soil Science and Plant Nutrition 36, 653–659.
Sawwan J,
Shibli RA,
Swaidat I, Tahat M
(2000) Phosphorus regulates osmotic potential and growth of African violet under in vitro-induced water deficit. Journal of Plant Nutrition 23, 759–771.
Schmidhalter U
(1997) The gradient between pre-dawn rhizoplane and bulk soil matric potentials, and its relation to the pre-dawn root and leaf water potentials of four species. Plant, Cell & Environment 20, 953–960.
| Crossref | GoogleScholarGoogle Scholar |
Schmidhalter U, Oertli JJ
(1991) Germination and seedling growth of carrots under salinity and moisture stress. Plant and Soil 132, 243–251.
Schmidhalter U,
Burucs Z, Camp KH
(1998a) Sensitivity of root and leaf water status in maize (Zea mays) subjected to mild soil dryness. Australian Journal of Plant Physiology 25, 307–316.
Schmidhalter U,
Evéquoz M,
Camp KH, Studer C
(1998b) Sequence of drought response of maize seedlings in drying soil. Physiologia Plantarum 104, 159–168.
| Crossref | GoogleScholarGoogle Scholar |
Scholander PF,
Hammel HT,
Bradstre ED, Hemmings EA
(1965) Sap pressure in vascular plants – negative hydrostatic pressure can be measured in plants. Science 148, 339–342.
| Crossref | GoogleScholarGoogle Scholar |
Serraj R, Sinclair TR
(2002) Osmolyte accumulation: can it really help increase crop yield under drought conditions? Plant, Cell & Environment 25, 333–341.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Sharp RE, Davies WJ
(1979) Solute regulation and growth by roots and shoots of water-stressed maize plants. Planta 147, 43–49.
| Crossref | GoogleScholarGoogle Scholar |
Sharp RE,
Poroyko V,
Hejlek LG,
Spollen WG,
Springer GK,
Bohnert HJ, Nguyen HT
(2004) Root growth maintenance during water deficits: physiology to functional genomics. Journal of Experimental Botany 55, 2343–2351.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Smika D,
Haas H, Power W
(1965) Effects of moisture and nitrogen fertilizer on growth and water use by native grass. Agronomy Journal 57, 483–486.
Sponchiado BN,
White JW,
Castillo JA, Jones PG
(1989) Root growth of 4 common bean cultivars in relation to drought tolerance in environments with contrasting soil types. Experimental Agriculture 25, 249–257.
Subbarao GV,
Johansen C,
Slinkard AE,
Rao RCN,
Saxena NP, Chauhan YS
(1995) Strategies for improving drought resistance in grain legumes. Critical Reviews in Plant Sciences 14, 469–523.
Turner NC
(1988) Measurement of plant status by the pressure chamber technique. Irrigation Science 9, 289–293.
| Crossref | GoogleScholarGoogle Scholar |
Turner NC,
Stern WR, Evans P
(1987) Water relations and osmotic adjustment of leaves and roots of lupins in response to water deficit. Crop Science 27, 977–983.
Voetberg GS, Sharp RE
(1991) Growth of the maize primary root at low water potentials. 3. Role of increased proline deposition in osmotic adjustment. Plant Physiology 96, 1125–1130.
| PubMed |
Wolf T,
Heidelmann T, Marten I
(2006) ABA regulation of K+-permeable channels in maize subsidiary cells. Plant & Cell Physiology 47, 1372–1380.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Yambao EB, O’Toole JC
(1984) Effects of nitrogen nutrition and root medium water potential on growth, nitrogen uptake and osmotic adjustment of rice. Physiologia Plantarum 60, 507–515.
| Crossref | GoogleScholarGoogle Scholar |