Objective To identify the NLP family members in moso bamboo (Phyllostachys edulis) and lay a foundation for further study on the molecular regulation mechanism of these NLPs.

Method The molecular characteristics of the NLP members in moso bamboo were identified and analyzed comprehensively by bioinformatics methods, and the expression patterns of the NLPs in response to nitrogen were detected by quantitative real-time PCR (qPCR).

Result Ten NLP members (PeNLP1～PeNLP10) were identified from moso bamboo. The length of PeNLPs ranged from 714 aa to 963 aa, with the molecular weight of 77.41～105.08 kDa, and the theoretical isoelectric point ranged from 5.36 to 6.25. The prediction of subcellular localization showed that all PeNLPs were located in the nucleus except PeNLP9 in the chloroplast. Phylogenetic analysis showed that PeNLPs could be divided into 3 groups with 4, 2 and 4 members, respectively. All PeNLPs contained 4 introns, and there were some differences in the size and position of introns among different members. There were 6 collinear gene pairs in PeNLPs and 9 collinear gene pairs between PeNLPs and OsNLPs, and their Ka/Ks were all less than 1.0, indicating that they had undergone purification selection in evolution. Tissue specific analysis showed that some PeNLPs expressed in tissue-specific manner, while some PeNLPs expressed constitutively. The expression of PeNLPs was induced by nitrogen starvation, and that of PeNLP1 was significantly up-regulated within 1 hour, while those of other 5 PeNLPs were significantly down-regulated (p < 0.01). After 72 hours of nitrogen starvation, the seedlings were resupplied with nitrogen, and the expression levels of all PeNLPs were significantly up-regulated (p < 0.05 or p < 0.01) within 24 hours.

Conclusion There are 10 members of NLP family identified in moso bamboo. There are some differences in molecular characteristics and tissue expression specificity of each member. The expression of PeNLPs can respond to nitrogen starvation rapidly, and it is significantly up-regulated in the process of nitrogen resupply after nitrogen starvation.