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Plant Growth Regul (2010) 60:99104 DOI 10.1007/s10725-009-9424-6
ORIGINAL PAPER
Role of some growth regulators on cytogenetic activity of barley under salt stress
Selma Tabur Kymet Demir
Received: 6 April 2009 / Accepted: 30 November 2009 / Published online: 10 December 2009 Springer Science+Business Media B.V. 2009
Abstract The effects of gibberellic acid (GA3), kinetin (KIN), benzyladenine and ethylene (E) on mitotic activity and chromosomal aberrations in root tips of barley seeds (Hordeum vulgare L. cv. Blbl 89) germinated under salt stress were investigated. It was determined that all of these plant growth regulators (PGRs) decreased mitotic index in root tips of barley seeds germinated at 20 C and in distilled water. Furthermore, some of the PGRs studied increased signicantly the frequency of chromosomal aberrations. The frequency of chromosomal aberrations in seeds treated with E and KIN was considerably higher than in the seeds germinated under nonstress conditions. The inhibitory effect of salt stress on mitotic index increased with increasing salt concentration (0.30, 0.35, 0.40 and0.45 molal, m). GA3 and KIN pretreatments showed a successful performance in ameliorating the negative effects of increasing salinity on mitotic activity. The number of chromosomal aberrations also increased with increasing NaCl concentration. However, most of the PGR pretreatments studied alleviated the detrimental effects of increasing salinity on chromosomal aberrations. KIN pre-treatment at 0.30 and 0.35 m salinity could not rescued the cytogenetic activity of salt stress on this parameter.
Keywords Barley root-tips Chromosomal aberrations
Mitotic index Plant growth regulators Salinity
Introduction
Environmental stresses affects plant growth and development (Swiatek et al. 2003). Salinity is one of the most common environmental stress factors. Salts, such as carbonate, sulphate, chloride, nitrate and borate in soil structure impair plant growth and development (Tobe et al. 2003). Salinity adversely affects plant growth and development, hindering seed germination (Dash and Panda 2001), seedling growth (Ashraf et al. 2002), enzime activity (Prakash and Prathapasenan 1988), DNA, RNA and protein synthesis (Anuradha and Rao 2001) and mitosis (Bozcuk 1978). However, plant species differ in their sensitivity or tolerance to salt stress (Cony and Trione 1998; Ashraf and Harris 2004). There have been numerous studies of the effects of salinity on plants (Greenway and Munns 1980; Munns 1993; Iqbal and Ashraf 2005; Jamil et al. 2007; Duan...