| The two-line hybrid rice technology has provided a new technological approach of utilization of heterosis in rice in China,and verifying the regulation mechanism of fertility transformation of male sterile lines is the key point for this theory and applying basic research.From the photoperiod-sensitive genic male sterile lines transcriptome difference results,we obtained JA biosynthesis pathway DEGs;long and short light condition treatments were used to induce the fertility transformation of NK58 S,the photoperiod-sensitive genic male sterile line and D52 S,the short photoperiod-sensitive genic male sterile line.The leaf of NK58 S and D52 S at panical development stage 5,6,7 were used for measuring JA content,LOX,AOS,AOC and OPR enzyme activity,we also used q PCR to analyse the gene expression difference of LOX,AOS,AOC and OPR.The main results are as follows.1.The pollen fertility of NK58 S and D52 S can be changed effectively under long(14h)and short(10h)light condition.Fertility transformation of the two lines were opposite in the same environmental conditions: NK58 S is male sterility under natural light conditions,and short light treatment can make the pollen fertile;but short light treatment can make the pollen sterile,and the pollen is fertile under natural long light condition in D52 S.2.The transcriptome datas of the two lines under sterile and fertile light condition were obtained.It showed that both of the two lines had 44 common DEGs under the photoperiod treatment,but the DEGs numbers in the two lines were different,and the up-regulate or down-regulate trends were not consistent with each other;p-value<0.05 of significance test and FC?2 were used as standards for screening DEGs,and the fertile materials were used as reference.We found 1,036 DEGs totally,451 down-regulate DEGs and 585 up-regulate DEGs in D52S;140 DEGs were found in NK58 S,39 DEGs were up-regulate and 101 were down-regulate.In addition,the DEGs,LOX,AOS,AOC and OPR,which belonged to JA synthesis pathway were also screened from transcriptome datas and GO enrichment results.3.In the results of JA content in the leaves,the JA content of fertile material was higher than sterile material at stage 6 and stage 5 in NK58 S and D52 S after the long and short light treatments,respectively.And both of the JA content of two lines have significant difference during all stages,it is indicated that the long and short light condition can affect JA biosynthesis continuously during the growth and development process of rice.The pollen I2-KI dyeing rate of spraying MEJA were 39.24 and 118.6 times of sterile materials,respectively;the pollen I2-KI dyeing rate of fertile materials in NK58 S was34.47 times of spraying SHAM,and D52 S was sterile completely after spraying MEJA.The JA content,OPR,LOX,AOC and AOS enzyme activity can be improved after spraying MEJA,but SHAM cannot reduce the enzyme activity and JA content,we speculated it may be associated with late sampling periods,the inhibiting effect of SHAM was not obvious.4.The result of q PCR showed that the expression levels of LOX,AOS,AOC and OPR genes in fertile materials were higher than sterile materials at stage 5 and 6 in the two lines.The relative expression levels of these 4 genes can be increased or reduced after spraying MEJA or SHAM consistently.It suggested that the effects of these two treatments mainly played a role in controlling the gene expression of JA biosynthesis pathway to finish fertility transformation.This study obtained that the long and short photoperiod-sensitive genic male sterile lines NK58 S and D52 S fertility transformation characteristics and the enzyme activity and gene expression of LOX,AOS,AOC and OPR in JA synthesis pathway under long and short light conditions and exogenous spraying MEJA and SHAM treatments,it provided preliminary evidence for fertility transformation,however,it's clearly that it needs further research to clarify internal mechanisms. |
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