title: A new screening technique for salinity resistance in rice (Oryza sativa L.) seedlings using bypass flow.
abstract: A lack of screening techniques delays progress in research on salinity resistance in rice. In this study, we report our test of the hypothesis that an apoplastic pathway (the so-called bypass flow) causes a difference in salt resistance between rice genotypes and can be used in screening for salinity resistance. Fourteen-day-old seedlings of low- and high-Na(+) -transporting recombinant inbred lines (10 of each) of rice IR55178 were treated with 50 mm NaCl and 0.2 mm trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), a bypass flow tracer, for short (4 d) and long (90 d) periods of time. The results showed that the average shoot Na(+) concentration and bypass flow for high-Na(+) -transporting lines were 1.4 and 2.4 times higher than those of low-Na(+) -transporting lines, respectively. There was a positive linear correlation between the percentage of bypass flow and Na(+) concentrations in the shoots, suggesting that the difference in Na(+) transport in rice is a consequence of different degrees of bypass flow. Moreover, a high correlation was found between bypass flow and seedling survival after prolonged salt stress: the lower the magnitude of bypass flow, the greater the seedling survival. We conclude that bypass flow could be used as a new screening technique for salt resistance in rice.
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK. b.faiyue@gmail.com
authors.forename: Bualuang
authors.initials: B
authors.lastname: Faiyue
authors.forename: Mohammed J
authors.initials: MJ
authors.lastname: Al-Azzawi
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Flowers
mesh_terms: D001692:Biological Transport; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D055051:Salt-Tolerant Plants / Q000502:physiology*; D036226:Seedlings / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D012965:Sodium Chloride; D012964:Sodium