Effect of salinity stress on growth and carbohydrate metabolism in three Rice (Oryza sativa L.) cultivars differing in salinity tolerance

Applied Taxonomic Research Center, Department of Biology Faculty of Science, Khon Kaen University, Khon Kaen, 40002 Thailand.
Indian journal of experimental biology (Impact Factor: 0.84). 11/2008; 46(10):736-42.
Source: PubMed


Rice seedlings cv. Khao Dawk Mali 105 (salt-sensitive), Luang Anan (moderately salt-tolerant) and Pokkali (salt-tolerant) were exposed to 0, 50, 100 and 150 mM NaCI for 9 d. Salinity stress caused reduction in leaf relative water contents in all cultivars. Shoot length of cv. Pokkali was least affected by salinity stress whereas increased root length in response to salinity stress was apparent in cvs. Khao Dawk Mali 105 and Luang Anan. Increased salinity level also caused reduction in fresh and dry weights in cvs. Khao Dawk Mali 105 and Luang Anan, but had no effect in cv. Pokkali except at 150 mM. Accumulation of total soluble sugars and sucrose in mature leaves were observed in cv. Khao Dawk Mali 105 exposed to high level of salinity whereas their concentrations in cvs. Luang Anan and Pokkali remained the same as control plants. Accumulation of sucrose in cv. Khao Dawk Mali 105 was suggested to be resulted from the alteration of photosynthate partitioning since the activities of sucrose phosphate synthase were not affected by salinity in this cultivar. On the contrary, salinity stress induced an accumulation of starch in cv. Pokkali. It is suggested that partitioning sugars into starch may involve in salinity tolerance by avoiding metabolic alterations.

Download full-text


Available from: Maysaya Thitisaksakul, Jan 15, 2014
  • Source
    • "Toleransi juga terkait erat dengan varietas padi karena setiap varietas mengembangkan derajat toleransi cekaman garam yang berbeda-beda pada level kecambah (Abbas et al. 2013). Kemampuan tanaman untuk tumbuh pada kondisi cekaman garam akan menentukan distribusi dan produktifitasnya (Pattanagul & Thitisaksakul 2008). Peningkatan kadar garam pada tanah pertanian diramalkan berdampak pada hilangnya 30% tanah pertanian 25 tahun yang akan datang, dan 50% di tahun 2050 (Wang et al. 2003). "
    [Show abstract] [Hide abstract]
    ABSTRACT: AbstractThe salt-stress tolerant rice varieties are very important to overcome the salt stress in coastal area. This study was aimed to analyze the responses of shoot and root of seedlings of six rice varieties to the salt stress. The rice varieties used in this study were obtained from Kecamatan Bantan, Kabupaten Bengkalis. The varieties were Amat Candu, Sadani, Solok, and Yamin. The two rice varieties, namely IR64 and Indragiri, were used as the comparation group. This study was conducted using Randomized Block Design with two factors and three replications. The first factor was salt (NaCl) concentration, i.e 0 mM (control), 15 mM, 30 mM, and 45 mM. The second factor was six rice varieties. The results showed that the seedling roots growth in Amat Candu was faster when compared to the others. According to the seedling roots growth, Indragiri was the salt tolerant rice variety, Amat Candu was the salt moderate rice variety, and IR64, Sadani, Yamin, and Solok were the salt sensitive rice varieties. Beside that, the seedling roots growth was the best parameter to study the salt tolerance in rice.
  • Source
    • "Accordingly, studies have been conducted in the past to investigate salttolerant genotypes of rice crop, i.e. Pokkali, FL478 (isogenic line derived from PokkaliIR29), HJ, IR651 and CSR-1, as model objects (Dubey and Singh, 1999; Pattanagul and Thitisaksakul, 2008; Cha-um et al., 2009; Ferdose et al., 2009; Nemati et al., 2011; Platten et al., 2013; Sarkar et al., 2013). Previously, we have investigated carbohydrate-related gene(s) expression (mRNA), biochemical, physiological and morphological changes in photoautotrophically grown rice seedlings exposed to NaCl stress under in vitro conditions (Cha-um et al., 2009; Theerawitaya et al., 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Salt-affected soil is one of the most important abiotic stresses, leading to reduce rice productivity in many region of the world. The objective of this investigation was to determine the Na+, soluble sugar and starch contents and expression of some starch-related genes in two genotypes, Pokkali (salt tolerant) and IR29 (salt sensitive), grown under 200 mM NaCl. Three-week-old rice seedlings cvs. Pokkali and IR29 were treated with 0 or 200 mM NaCl subsequently Na+, starch content, soluble sugar and growth characters were evaluated. The Na+ concentration in salt-stressed seedlings cv. IR29 was reached following leaf sheath>leaf blade>root tissues. Na+ accumulation in leaf blade and leaf sheath was positively related to soluble sugar enrichment (r2>0.68). In starch biosynthesis, OsAGPS2b mRNA expression in leaf blade of rice seedlings cv. Pokkali was up-regulated for 66%, when exposed to 200 mM NaCl for 48h, leading to starch accumulation. Soluble starch content in salt-stressed seedlings was peaked to 68.84 μg g-1 FW in the leaf blade of cv. Pokkali and 165.83 μg g-1 FW in leaf sheath of cv. IR29 which was confirmed by iodine dye staining. In cv. Pokkali, soluble starch in the leaf blade of salt-stressed seedlings was enhanced and correlated with Na+ gathering CoroNa green emission. Growth performances of indica rice cv. IR29 seedlings were significantly declined when subjected to salt stress for 4 d. Na+ absorption by root tissue was greater in IR29 than that in Pokkali. The starch concentration in salt-stressed seedlings of cv. Pokkali was the maximum to 68.8 μg g-1 FW in the leaf blade, and it related to up-regulated levels of OsAGPS2b mRNA and OsGPL1. The study concludes that the regulation of carbohydrate metabolism in salt tolerant cultivar of rice may play a key role as a major salt defense mechanism when seedlings subjected to 200 mM NaCl.
    Plant Omics 01/2015; 8(2):130-140. · 0.78 Impact Factor
  • Source
    • "Similar conclusions were recorded by Khajeh-Hosseini et al. (2003), Jamil et al. (2006), Munns et al. (2006), Maghsoudi Moud and Maghsoudi (2008) and McGrath and Reyes (2008). Pattanagule and Thitisaksakul (2008) reported that carbohydrates are accumulated in plant tissues under saline condition and these substances are suspected of contributing to osmotic adjustment. Khavari- Nejad et al. (2008), Hajiboland et al. (2009), Dadkhah (2010) and Saadat et al. (2012) indicated that germination characters i.e. germination percentage and SVI were decreased as salinity concentration increased. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The response of six sugar beet genotypes (Raspoly, Nada, Strube, Almaz, Toro, Oskarpoly) under seven salinity levels (distilled water as control, 1500, 3000, 45000, 6000, 7500 and 9000 ppm NaCl) and soaking in gibberellic acid levels were studied on germination parameters. An experiment with factorial arrangement was conducted by using randomize complete block design with four replications. Seed soaking in GA3 significantly affected final germination percentage (FGP), mean germination time (MGT), coefficient velocity (CV), seedling vigor index (SVI), energy of germination (EG), emergence rate (ER) and speed of germination (SG). Highest averages of FGP, CV, SVI, EG, ER and SG, were produced from soaking seed in 200 ppm of GA3. Moreover, highest averages of MGT were recorded from soaking sugar beet seed in the control treatment. Sugar beet cultivars significantly differed in FGP, MGT, CV, SVI, EG, ER and SG. Highest averages of FGP, MGT, CV, SVI, EG, ER and SG were recorded with sown Raspoly cultivar. Increasing salinity concentrations from 0 to 9,000 ppm significantly decreased FGP, CV, SVI, EG, ER and SG. While, MGT increased with increasing salinity concentrations. Results of means comparison showed that in all genotypes, there was a decrease in germination percentage due to salinity stress increment and maximum germination percentage was delayed. The interaction between cultivars and seed soaking in GA3 levels significantly affected FGP, MGT, CV and SVI. The interaction between seed soaking in GA3 levels and salinity concentrations significantly affected FGP, MGT and SVI.
    Sugar Tech 06/2014; 16(2). DOI:10.1007/s12355-013-0252-7 · 0.58 Impact Factor
Show more