| Using rice (Oryza saliva L.) less-lateral-root mutant llr and its wild type ' IRS'as materials, effect of jasmonic acid (JA) on lateral root (LR) formation and its relationship with auxins were studied, and its relationship with salicylic acid (SA) were also studied based on the preparation of monoclonal antibodies to SA and establishment of an enzyme-linked immunosorbent assay (ELISA) for detect SA in plants.1. Promotion effect of JA on LR formation in rice seedlingSeminal roots of 2-day-old seedlings of the less-lateral- root mutant llr rice and its wild type 'IR8' were treated with JA solution for 48h. Results showed that the elongation rate of seminal roots in both llr and 'IR8' were similar and proportionally reduced with the increase of JA concentration (0.016-50 umol/L). While the number of lateral roots per centimeter (NLRC) increased correlated with JA concentration only within a less ranges (0.016-2.0 umol/L). High concentration (10 umol/L) of JA, promoted lateral root formation in distal zone formed during and after treatment, but decreased NLRC in basal zone formed before treatment due to serious inhibition of lateral root formation. On the other hand, the formation of root hairs in the distal zone was inhibited, and even fully blocked by JA over 1 umol/L. The effects of JA on increasing LRs and decreasing root hairs in the distal zone could last at least to the 7th day after the removing of JA solution from the treated roots. No difference could be seen between llr and 'IR8' on the aspects of seminal root elongation, LR and root hairs formation in response to JA, thus llr mutation might not involve in the signaling transduction of JA in inducing LR formation.2. Relationship between JA and auxins on LR formation in rice seedlingIn both less-lateral-root mutant llr and its wild type 'IR8', exogenous IB A (indole-3-butyric acid) could promote LR formation in the basal zone of seminal root, and the NLRC increased as the IBA concentration increased. Exogenous IAA (indole-3-acetic acid), however, failed to induce additional LRs in both llr and 'IR8'. In the aspect ofseminal root elongation, llr showed enhanced resistance to IBA and IAA. Though both IBA and IAA caused inhibition of seminal root elongation and promotion of LRs elongation, IAA required a more than 20-fold concentration. While JA promoted LR formation in distal zone and llr did not show enhanced resistance to JA in seminal root elongation than that of 'IR8'. Thus we conclude that JA might be one of the potent factors, other than auxin, involving in the regulation of LR formation.3. Relationship between JA and SA on LR formation in rice seedlingMouse monoclonal antibodies (McAbs) against salicylic acid (SA) was produced and characterized for the first time. The McAb S2-8F, were derived from an immunogen in which 5-aminosalicylic acid (5-ASA) was conjugated to KLH (hemocyanin from keyhole limpets) through its (Cs)-NH2 group. The antibody showed high specificity to SA and even more high specificity to 5-ASA (the cross-reaction is 144.8%), but very little cross-reactivity with 5- sulfosalicylic acid (0.9%) and 4-aminosalicylic acid (0.3%). Other compounds structurally similar to S A, such as 4-hydroxybenzoic acid, 4-aminobenzoic acid and salicylaldoxime, were not found to exhibit any cross-reactivity. Based on this antibody, a direct enzyme-linked immunosorbent assay (ELISA) with high sensitivity and precision was developed which displayed a linear range from 0.0195 nmol to 20 nmol of SA. Test results by the developed ELISA showed that SA levels in rice seedling were altered by JA treatment. Results of exogenous experiments showed that SA inhibited LR formation and the intensity was corrected with concentrations, though SA also inhibited seminal root elongation as that of JA. Results also showed that SA could reversed the inhibition effect of JA on root hairs formation.In summary, our experimental results show that JA can promote LR formation, while SA inhibit LR formation. Promotion effect of JA on LR forma...
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