A cold responsive galactinol synthase gene from Medicago falcata (MfGolS1) is induced by myo‐inositol and confers multiple tolerances to abiotic stresses. Issue 1 (28th January 2013)

• Record Type: Journal Article
• Authors: Zhuo, Chunliu; Wang, Ting; Lu, Shaoyun; Zhao, Yaqing; Li, Xiaoguang; Guo, Zhenfei
• Is Part Of: Physiologia plantarum. Volume 149:Issue 1(2013:Sep.)
• Page Start: 67
• Page End: 78
• Publication Date: 2013-01-28
• Subjects: Plant physiology -- Periodicals; 571.2
• DOI: 10.1111/ppl.12019
• Languages: English
• ISSNs: 0031-9317

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Galactinol synthase (GolS, EC 2.4.1.123) catalyzes formation of galactinol and the subsequent synthesis of raffinose family oligosaccharides. The relationship of GolS to drought and salt tolerance has been well documented, however, little information is available about the role of <italic>GolS</italic> gene in cold tolerance. A coding sequence of <italic>MfGolS1</italic> cDNA was cloned from <italic>Medicago sativa</italic> spp <italic>falcata</italic> (i.e. <italic>M. falcata</italic>), a species that exhibits greater cold tolerance than alfalfa (<italic>M. sativa</italic>). <italic>MfGolS1</italic> transcript was not detected in untreated vegetative tissues using RNA blot hybridization; however, it was greatly induced in leaves, but not in stem and petiole, after cold treatment. Higher levels of <italic>MfGolS1</italic> transcript were induced and maintained in <italic>M. falcata</italic> than in <italic>M. sativa</italic> during cold acclimation. Accordingly, more sugars including sucrose, galactinol, raffinose and stachyose were accumulated in <italic>M. falcata</italic> than in <italic>M. sativa</italic>. The data indicated that <italic>MfGolS1</italic> transcript and its resultant sugar accumulation were associated with the differential cold tolerance between <italic>M. falcata</italic> and <italic>M. sativa</italic>. <italic>MfGolS1</italic> transcript was weakly induced by dehydration and salt stresses, but not responsive to abscisic acid. <italic>MfGolS1</italic> could be induced by <italic>myo</italic>‐inositol, which is proposed to participate in cold‐induced <italic>MfGolS1</italic> expression. Overexpression of <italic>MfGolS1</italic> in tobacco resulted in elevated tolerance to freezing and chilling in transgenic plants as a result of enhanced levels of galactinol, raffinose and stachyose. Tolerance to drought and salt stresses was also increased in the transgenic tobacco plants. It is suggested that <italic>MfGolS1</italic> plays an important role in plant tolerance to abiotic stresses.</p> </abstract>