Figure legends
Figure 1. The location of study site in Zhangjiang Estuary, Yunxiao, Fujian, China. Salinity in oligohaline upstream site ranged from 0‰ to 6‰, salinity in mesohaline midstream site ranged from 13‰ to 18‰ and salinity in euhaline downstream site ranged from 29‰ to 32‰.
Figure 2. Tiller number and plant height of Spartina alterniflora in three study sites. (a) The number of tillers per seedlings and (b) plant height were recorded every month. The solid square represents seedlings grew at oligohaline (0-6‰) site, the open circle represents seedlings grew at mesohaline (13-18‰) site, the solid triangle represents seedlings grew at euhaline (29-32‰) site.
Figure 3. The phenotype of Spartina alterniflora tillering under 0‰, 15‰, 30‰ salinity in different developmental stages. The S. alterniflora seedlings were grown in greenhouse for 5 months. The different developmental stages of tillers were recorded by steremicroscope M165 FC (Leica, Germany). (a) 30 days; (b) 90 days; (c) 150 days. The red triangles represent the tillers.
Figure 4. The effect of salinity on tillering of Spartina alternifloragrown under greenhouse condition. (a) percentage of tillering; (b) number of tiller per seedling; (c) plant height. The solid square represents seedlings treated with 0‰ salinity, the open circle represents seedlings treated with 15‰ salinity, the solid triangle represents seedlings treated with 30‰ salinity.
Figure 5. The expression level of genes related to strigolactone biosynthesis and signal transduction in various tissues of Spartina alterniflora . (a) SaD10 ; (b) SaD17 ; (c) SaD14 ; (d)SaD53 . The gene expression levels were analyzed by using the 2-△△CT method with SaTublin as reference gene. S: stem; N: basal node of the main stem; R: root; RH: rhizome; B: bud; L: leaf.
Figure 6. The expression levels of genes related to strigolactones biosynthesis and signal transduction under different salinities inSpartina alterniflora . (a) SaD10 ; (b) SaD17 ; (c)SaD14 ; (d) SaD53. SaTublin was use as reference gene.
Figure 7 . The regulation mechanism of salinity on tillering process inSpartina alterniflora . The red words represent a high expression level of genes or content of SLs, the green words represent a low expression level of genes or content of SLs. “┬” means reduction and the red arrow means promotion. (a) 0‰ salinity condition; (b) 15‰ salinity condition; (c) 30‰ salinity condition.
Table 1. The content of strigolactones and its derivatives under different salinity treatments in Spartina alterniflora roots. ND means 5-DS or strigol was not detected.
Supplementary Table S1. The selected reaction monitoring conditions for protonated or deprotonated strigolactones ([M+H+]).
Supplementary Table S2. The degenerate primers used for sequence cloning in Spartina alterniflora .
Supplementary Table S3. The sequences of SaD10 ,SaD17 , SaD14 and SaD53 in Spartina alterniflora .
Supplementary Table S4. Cloning and qRT-PCR primer design of genes related to strigolactones biosynthesis and signal transduction inSpartina alterniflora . The cloned sequences were aligned to NCBI database.