Plant Growth Regulation

, 57:281

Effects of SAG12-ipt expression on cytokinin production, growth and senescence of creeping bentgrass (Agrostis stolonifera L.) under heat stress

  • Yan Xu
  • Jiang Tian
  • Thomas Gianfagna
  • Bingru Huang
Original Paper

Abstract

The study was conducted to determine the effects of expression of a transgene encoding adenine isopentenyl transferase (ipt), which controls cytokinin synthesis, on growth and leaf senescence of creeping bentgrass (Agrostis stolonifera L.), subjected to heat stress. Creeping bentgrass (cv. Penncross) was transformed with ipt ligated to a senescence-activated promoter (SAG12). Eight SAG12-ipt transgenic lines exhibiting desirable turf quality and a transgenic control line (transformed with the empty vector) were evaluated for morphological and physiological changes under normal growth temperature (20°C) and after 14 days of heat stress (35°C) in growth chambers. Six of the SAG12-ipt lines developed more tillers than the control line during establishment under normal growth temperature of 20°C. Following 14 days of heat stress, four of the SAG12-ipt lines had increased 65–83% of roots and for all six SAG12-ipt lines root elongation continued, whereas root production ceased and total root length decreased for the control line. Root isopentenyl adenine (iPA) content increased 2.5–3.5 times in five of the SAG12-ipt lines, whereas in the control line iPA decreased 20% after 14 days at 35°C. Total zeatin riboside (ZR) content was maintained at the original level or increased in five of the SAG12-ipt lines, whereas in the control line ZR decreased under heat stress. Our results suggest expression of SAG12-ipt in creeping bentgrass stimulated tiller formation and root production, and delayed leaf senescence under heat stress, suggesting a role for cytokinins in regulating cool-season grass tolerance to heat stress.

Keywords

Isopentnyltransferase Senescence-activated promoter High temperature Leaf senescence 

Abbreviations

iPA

Isopentenyl adenine

ZR

Zeatin riboside

ipt

Isopentenyl transferase

SAG

Senescence-activated promoter

DMSO

Dimethyl sulfoxide

References

  1. Arnon DI (1949) Copper enzymes in isolated chloroplasts. Polyphenoloxidase in Befa vulgaris. Plant Physiol 24:1–13PubMedCrossRefGoogle Scholar
  2. Clark DG, Dervinis C, Barret JE, Klee H, Jones M (2004) Drought-induced leaf senescence and horticultural performance of transgenic P-SAG12-IPT petunias. J Am Soc Hortic Sci 129:93–99Google Scholar
  3. Eberle J, Arnscheidt A, Klix D, Weiler EW (1986) Monoclonal antibodies to plant growth regulators: III. Zeatinriboside and dihydrozeatinriboside. Plant Physiol 81:516–521PubMedCrossRefGoogle Scholar
  4. Gan SS, Amasino RM (1995) Inhibition of leaf senescence by autoregulated production of cytokinin. Science 270:1986–1988. doi:10.1126/science.270.5244.1986 PubMedCrossRefGoogle Scholar
  5. Gan SS, Amasino RM (1996) Cytokinins in plant senescence: from spray and pray to clone and play. Bioessays 18:557–565. doi:10.1002/bies.950180707 CrossRefGoogle Scholar
  6. Gan SS, Amasino RM (1997) Making sense of senescence-molecular genetic regulation and manipulation of leaf senescence. Plant Physiol 113:313–319Google Scholar
  7. Geng S, Ma M, Ye HC, Liu BY, Li GF, Chong K (2001) Effects of ipt gene expression on the physiological and chemical characteristics of Artemisia annua L. Plant Sci 160:691–698. doi:10.1016/S0168-9452(00)00453-2 CrossRefGoogle Scholar
  8. Hewelt A, Prinsen E, Schell J, Van Onckelen H, Schmulling T (1994) Promoter tagging with a promoterless ipt gene leads to cytokinin-induced phenotypic variability in transgenic tobacco plants: implications of gene dosage effects. Plant J 6:879–891. doi:10.1046/j.1365-313X.1994.6060879.x PubMedCrossRefGoogle Scholar
  9. Hu YL, Jia WL, Wang JD, Zhang YQ, Yang LL, Lin ZP (2005) Transgenic tall fescue containing the Agrobacterium tumefaciens ipt gene shows enhanced cold tolerance. Plant Cell Rep 23:705–709. doi:10.1007/s00299-004-0863-2 PubMedCrossRefGoogle Scholar
  10. Huynh LN, VanToai T, Streeter J, Banowetz G (2005) Regulation of flooding tolerance of SAG12: ipt Arabidopsis plants by cytokinin. J Exp Bot 56:1397–1407. doi:10.1093/jxb/eri141 CrossRefGoogle Scholar
  11. Ivic SD, Sicher RC, Smigocki AC (2001) Growth habit and sugar accumulation in sugarbeet (Beta vulgaris L.) transformed with a cytokinin biosynthesis gene. Plant Cell Rep 20:770–773. doi:10.1007/s002990100389 CrossRefGoogle Scholar
  12. John I, Drake R, Farrell A, Cooper W, Lee P, Horton P, Grierson D (1995) Delayed leaf senescence in ethylene-deficient ACC-oxidase antisense tomato plants—molecular and physiological analysis. Plant J 7:483–490. doi:10.1046/j.1365-313X.1995.7030483.x CrossRefGoogle Scholar
  13. Jordi W, Schapendonk A, Davelaar E, Stoopen GM, Pot CS, De Visser R, Van Rhijn JA, Gan S, Amasino RM (2000) Increased cytokinin levels in transgenic P-SAG12-IPT tobacco plants have large direct and indirect effects on leaf senescence, photosynthesis and N partitioning. Plant Cell Environ 23:279–289. doi:10.1046/j.1365-3040.2000.00544.x CrossRefGoogle Scholar
  14. Khodakovskaya M, Li Y, Li JS, Vankova R, Malbeck J, McAvoy R (2005) Effects of cor15a-IPT gene expression on leaf senescence in transgenic Petunia × hybrida and Dendranthema × grandiflorum. J Exp Bot 56:1165–1175. doi:10.1093/jxb/eri109 PubMedCrossRefGoogle Scholar
  15. Khodakovskaya M, Zhao DG, Smith W, Li Y, McAvoy R (2006) Expression of ipt gene controlled by an ethylene and auxin responsive fragment of the LEACO1 promoter increases flower number in transgenic Nicotiana tabacum. Plant Cell Rep 25:1181–1192. doi:10.1007/s00299-006-0181-y PubMedCrossRefGoogle Scholar
  16. Li Q, Robson PRH, Bettany AJE, Donnison IS, Thomas H, Scott IM (2004) Modification of senescence in ryegrass transformed with IPT under the control of a monocot senescence-enhanced promoter. Plant Cell Rep 22:816–821. doi:10.1007/s00299-004-0762-6 PubMedCrossRefGoogle Scholar
  17. Liu XH, Huang BR, Banowetz G (2002) Cytokinin effects on creeping bentgrass responses to heat stress: I. Shoot and root growth. Crop Sci 42:457–465Google Scholar
  18. Luo YY, Gianfagna TJ, Janes HW, Huang B, Wang Z, Xing J (2005) Expression of the ipt gene with the AGPase s1 promoter in tomato results in unbranched roots and delayed leaf senescence. Plant Growth Regul 47:47–57. doi:10.1007/s10725-005-8647-4 CrossRefGoogle Scholar
  19. Mayak S, Halevy AH (1970) Cytokinin activity in rose petals and its relation to senescence. Plant Physiol 46:497–499PubMedCrossRefGoogle Scholar
  20. McCabe MS, Garratt LC, Schepers F, Jordi WJRM, Stoopen GM, Davelaar E, van Rhijn JHA, Power JB, Davey MR (2001) Effects of P-SAG12-IPT gene expression on development and senescence in transgenic lettuce. Plant Physiol 127:505–516. doi:10.1104/pp.127.2.505 PubMedCrossRefGoogle Scholar
  21. McGrady JJ, Struik PC, Ewing EE (1986) Effects of exogenous application of cytokinin on the development of potato (Solanum tuberosum L.) cuttings. Potato Res 29:191–205. doi:10.1007/BF02357650 CrossRefGoogle Scholar
  22. Murashige T, Skoog F (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant 15:473–497. doi:10.1111/j.1399-3054.1962.tb08052.x CrossRefGoogle Scholar
  23. Sakakibara H (2006) Cytokinins: activity, biosynthesis, and translocation. Annu Rev Plant Biol 57:431–449. doi:10.1146/annurev.arplant.57.032905.105231 PubMedCrossRefGoogle Scholar
  24. Schnablova T, Synkova H, Vicankova A, Burketova L, Eder J, Cvikrova M (2006) Transgenic ipt tobacco overproducing cytokinins overaccumulates phenolic compounds during in vitro growth. Plant Physiol Biochem 44(10):526–534PubMedCrossRefGoogle Scholar
  25. Setter TL, Flannigan BA, Melkonian J (2001) Loss of kernel set due to water deficit and shade in maize: carbohydrate supplies, abscisic acid, and cytokinins. Crop Sci 41:1530–1540Google Scholar
  26. Singh S, Letham DS, Palni MS (1992) Cytokinin biochemistry in relation to leaf senescence: VII. Endogenous cytokinin levels and exogenous applications of cytokinins in relation to sequential leaf senescence of tobacco. Physiol Plant 86:388–397. doi:10.1111/j.1399-3054.1992.tb01334.x CrossRefGoogle Scholar
  27. Swartzberg D, Dai N, Gan S, Amasino R, Granot D (2006) Effects of cytokinin production under two SAG promoters on senescence and development of tomato plants. Plant Biol 8:579–586. doi:10.1055/s-2006-924240 PubMedCrossRefGoogle Scholar
  28. Thomas JC, Smigocki AC, Bohnert HJ (1995) Light-induced expression of ipt from Agrobacterium-tumefaciens results in cytokinin accumulation and osmotic-stress symptoms in transgenic tobacco. Plant Mol Biol 27:225–235. doi:10.1007/BF00020179 PubMedCrossRefGoogle Scholar
  29. Van Loven K, Beinsberer S, Valcke R, Van Onckelen H, Clijsters H (1993) Morphometric analysis of the growth of Phsp70-ipt transgenic tobacco plants. J Exp Bot 44:1671–1678. doi:10.1093/jxb/44.11.1671 CrossRefGoogle Scholar
  30. Wang ZL, Pote J, Huang B (2003) Response of cytokinins, antioxidant enzymes, and lipid peroxidation in shoots of creeping bentgrass to high root-zone temperatures. J Am Soc Hortic Sci 128:648–655Google Scholar
  31. Xu Y, Huang B (2007) Heat-induced leaf senescence and hormonal changes for thermal bentgrass and turf-type bentgrass species differing in heat tolerance. J Am Soc Hortic Sci 132:185–192Google Scholar
  32. Zhang XZ, Ervin EH (2004) Cytokinin-containing seaweed and humic acid extracts associated with creeping bentgrass leaf cytokinins and drought resistance. Crop Sci 44:1737–1745Google Scholar
  33. Zhang J, Van Toai T, Huynh L, Preiszner J (2000) Development of flooding-tolerant Arabidopsis thaliana by autoregulated cytokinin production. Mol Breed 6:135–144. doi:10.1023/A:1009694029297 CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Yan Xu
    • 1
  • Jiang Tian
    • 1
  • Thomas Gianfagna
    • 1
  • Bingru Huang
    • 1
  1. 1.Department of Plant Biology and PathologyRutgers UniversityNew BrunswickUSA

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