Afterwards, the content of strigolactones and its derivatives inS. alterniflora roots were measured using the method of HPLC-MS/MS. It is surprising that the 5-DS was only detected in 0‰ salinity treatment and strigol was detected in 15‰ salinity treatment, while none of them could be detected in 30‰ salinity treatment. Even so, the content of 5-DS in 0‰ salinity treatment (0.1416 ± 0.0225 ng/g) was higher than the content of strigol (0.0632 ±0.0044 ng/g) in 15‰ salinity treatment (Table 1).
Furthermore, four genes which participate in strigolactone biosynthesis (D17 , D10 ) and signal transduction (D14 ,D53 ), were cloned from S. alterniflora . The fragment of these four genes were amplified by using the degenerate primers (Supplementary Table S2) and the sequences were acquired (Supplementary Table S3). After aligning against the NCBI database, these four genes were identified as SaD17 (87% Ident), SaD10 (83% Ident),SaD14 (91% Ident) and SaD53 (73% Ident) (Supplementary Table S4). We further designed the qRT-PCR primers and optimized the annealing temperature (Ta) for the qRT-PCR analysis (Supplementary Table S4).