期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1992
卷号：89
期号：17
页码：8394-8398
DOI：10.1073/pnas.89.17.8394
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Transgenic plants were constructed that express two foreign calmodulins (VU-1 and VU-3 calmodulins) derived from a cloned synthetic calmodulin gene. VU-1 calmodulin, similar to endogenous plant calmodulin, possesses a lysine residue at position 115 and undergoes posttranslational methylation. VU-3 calmodulin is a site-directed mutant of VU-1 calmodulin that is identical in sequence except for the substitution of an arginine at position 115 and thus is incapable of methylation. Both calmodulin genes, under the control of the cauliflower mosaic virus 35S promoter, were expressed in transgenic tobacco. Foreign calmodulin protein accumulated in plant tissues to levels equivalent to that of the endogenous calmodulin. All transformed lines of VU-1 plants were indistinguishable from untransformed controls with respect to growth and development. However, all transformed lines of VU-3 plants were characterized by decreased stem internode growth, reduced seed production, and reduced seed and pollen viability. The data suggest that these phenotypes are the result of the expression of the calmodulin mutant rather than the position of transferred DNA insertion or the overall alteration of calmodulin levels. Analyses of the activity of the purified transgenic calmodulins suggest that calmodulin-dependent NAD kinase is among the potential targets that may have altered regulation in VU-3 transgenic plants.
