Lotus japonicus nodulation is photomorphogenetically controlled by sensing the red/far red (R/FR) ratio through jasmonic acid (JA) signaling
Lotus japonicus nodulation is photomorphogenetically controlled by sensing the red/far red (R/FR) ratio through jasmonic acid (JA) signaling
复制标题
DOI：
10.1073/pnas.1105892108
复制
发表时间：
2011-10-04
影响因子：
11.1
通讯作者：
Hirsch, Ann M.
中科院分区：
文献类型：
--
作者：
Suzuki, Akihiro;Suriyagoda, Lalith;Hirsch, Ann M.
光对于为豆科植物和根瘤菌之间能量昂贵的固氮共生体提供碳至关重要。在这里，我们表明光敏色素 B (phyB) 是监测系统的一部分，用于检测次优光照条件，通常会抑制中索根瘤菌接种后的莲子根瘤发育。我们发现，与WT Miyakojima MG20相比，日本乳杆菌phyB突变体产生的根瘤数量显着减少。为了探索光同化物产生以外的原因，通过嫁接实验研究了根基因型发生局部控制的可能性。结果表明，芽而非根基因型负责根瘤的形成。为了探索光同化之外的系统控制机制，我们将 WT MG20 植物从白光转移到低或高红/远红 (R/FR) 光比例不同的条件。在低R/FR光照下，与在高R/FR光照下生长的植物相比，MG20根瘤的数量显着减少，尽管在低R/FR光照下生长的植物的光同化物含量较高。此外，低R/FR光生长的WT和白光生长的phyB突变体植物中茉莉酸（JA）响应基因的表达均降低，并且与phyB突变体中茉莉酰异亮氨酸含量的降低相关。此外，对在低R/FR光下生长的WT植物和在白光下生长的phyB突变体进行JA处理，感染线的形成和根瘤的形成都受到积极影响。总之，这些结果表明根瘤的形成是通过 JA 信号传导感应 R/FR 比率来控制光形态发生的。
Light is critical for supplying carbon to the energetically expensive, nitrogen-fixing symbiosis between legumes and rhizobia. Here, we show that phytochrome B (phyB) is part of the monitoring system to detect suboptimal light conditions, which normally suppress Lotus japonicus nodule development after Mesorhizobium loti inoculation. We found that the number of nodules produced by L. japonicus phyB mutants is significantly reduced compared with the number produced of WT Miyakojima MG20. To explore causes other than photoassimilate production, the possibility that local control by the root genotype occurred was investigated by grafting experiments. The results showed that the shoot and not the root genotype is responsible for root nodule formation. To explore systemic control mechanisms exclusive of photoassimilation, we moved WT MG20 plants from white light to conditions that differed in their ratios of low or high red/far red (R/FR) light. In low R/FR light, the number of MG20 root nodules dramatically decreased compared with plants grown in high R/FR, although photoassimilate content was higher for plants grown under low R/FR. Also, the expression of jasmonic acid (JA) -responsive genes decreased in both low R/FR light-grown WT and white light-grown phyB mutant plants, and it correlated with decreased jasmonoyl-isoleucine content in the phyB mutant. Moreover, both infection thread formation and root nodule formation were positively influenced by JA treatment of WT plants grown in low R/FR light and white light-grown phyB mutants. Together, these results indicate that root nodule formation is photomorphogenetically controlled by sensing the R/FR ratio through JA signaling.