V-ATPase and V-PPase at the Tonoplast Affect NO3Content in Brassica napus by Controlling Distribution of NO3Between the Cytoplasm and Vacuole

Yongliang Han, Qiang Liu, Jidong Gu, Jiming Gong, Chunyun Guan, Joe Eugene Lepo, Xiangmin Rong, Haixing Song*, Zhenhua Zhang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Nitrate, once taken up by plants, can either be stored in vacuoles or reduced by nitrate reductase in the cytoplasm. High accumulation of NO3 in the vacuole occurs when assimilation into the cytoplasm is saturated. This study elucidates how proton pumps at the tonoplast (V-ATPase and V-PPase) affect the NO3 content of Brassica napus by controlling the distribution of NO3 between the cytoplasm and vacuole. Pot experiments were conducted in a greenhouse under normal N (15.0 mM nitrate) conditions using B. napus genotypes that demonstrated either high (Xiangyou15) or low (814) nitrogen use efficiency (NUE). The NO3 content of the high NUE genotype was significantly lower than that of the low NUE genotype, whereas the total N per plant of the two genotypes was almost the same, suggesting that the different NUE between the two genotypes is not due to the difference of NO3 uptake. The relative expression levels of V-ATPase (vha-a3) and V-PPase (avp1) genes in the high NUE genotype were significantly lower than in the low NUE genotype, resulting in lower V-ATPase and V-PPase activities in the high NUE genotype. The transport of NO3 and protons from the cytoplasm to the vacuole is powered by V-ATPase and V-PPase, so their lower activities increase H+ efflux from and reduce NO3 influx into the vacuoles of the high NUE genotype. We conclude that the lower activity of proton pumps at the tonoplast is the main reason the high NUE genotype possesses lower NO3 content and higher N-use efficiency.

Original languageEnglish
Pages (from-to)22-34
Number of pages13
JournalJournal of Plant Growth Regulation
Volume34
Issue number1
DOIs
StatePublished - Mar 2015
Externally publishedYes

Keywords

  • Brassica napus
  • N-use efficiency
  • Nitrate
  • Nitrate reductase
  • Proton pumps in the tonoplast
  • Vacuole

Fingerprint

Dive into the research topics of 'V-ATPase and V-PPase at the Tonoplast Affect NO<sub>3</sub><sup>−</sup>Content in Brassica napus by Controlling Distribution of NO<sub>3</sub><sup>−</sup>Between the Cytoplasm and Vacuole'. Together they form a unique fingerprint.

Cite this