Genome‐wide identification, characterization, and expression analysis of the ammonium transporter gene family in tea plants (Camellia sinensis L.)

Abstract

As a preferred nitrogen form, ammonium (NH4+) transport via specific transporters is particularly important for the growth and development of tea plants (Camellia sinensis L.). However, our understanding of the functions of the AMT family in tea plants is limited. We identified and named 16 putative AMT genes according to phylogenetic analysis. All CsAMT genes were divided into three groups, distributed on 12 chromosomes with only one segmental duplication repetition. The CsAMT genes showed different expression levels in different organs, and most of them were expressed mainly in the apical buds and roots. Complementation analysis of yeast mutants showed that CsAMTs restored the uptake of NH4+. This study provides insights into the genome‐wide distribution and spatial expression of AMT genes in tea plants.

Transcriptome analysis of tea (Camellia sinensis) leaves in response to ammonium starvation and recovery

“…The strength of the nutrient solution was thereafter increased to 1/2 (for around 2 weeks) and full ( Zhang et al, 2018 ). The full nutrient solution contained the following nutrients: 1.5 mM (NH 4 ) 2 SO 4 , 0.73 mM KNO 3 , 0.1 mM KH 2 PO 4 , 0.46 mM K 2 SO 4 , 0.41 mM MgSO 4 , 0.5 mM CaCl 2 , 0.046 mM H 3 BO 3 , 0.09 mM MnSO 4 , 0.0091 mM ZnSO 4 , 0.002 mM CuSO 4 , 0.0026 mM Na 2 MoO 4 , and 0.032 mM Fe-EDTA ( Wang et al, 2022 ). After preculture for 1 month, tea seedlings with a similar appearance were chosen to be transferred to nutrient solution without N for 6 h (S_UN) or 7 days (L_UN) and controls were incubated at a normal NH 4 + level (3 mM NH 4 + ) for 6 h (CK1) or 7 days (CK2).…”

Nitrogen transport and assimilation in tea plant (Camellia sinensis): a review

“…In tea plants, CsAMTs expression seems to be tissue-specific: CsAMT1.2 reached the highest transcript abundance in roots, while CsAMT1.4 was mainly expressed in flower buds. However, CsAMT1.1 and CsAMT3.1 were highly expressed in all tissues, suggesting that these genes might have diverse functions in NH 4 + transport ( Zhang et al., 2018 ; Wang et al., 2022c ; Zhang et al., 2022a ). Likewise, AMTs expression levels are responsive to changes in NH 4 + availability.…”

“…Remarkably, CsAMT1.2 expression was significantly higher in roots than leaves under NH 4 + deficiency (0 mM NH 4 + ) or at 4 mM NH 4 + , demonstrating the major role of this transporter in NH 4 + uptake. Other genes involved in NH 4 + transport, such as CsAMT2.1b , CsAMT3.3 , CsAMT4.1a , CsAMT4.1b , CsAMT4.1c , and CsAMT4.1d , exhibited similar expression profiles, with a decreasing trend under low N supply and a notorious induction under high N supply ( Wang et al., 2022c ). Furthermore, this report indicates that CsAMTs expression in tea leaves is differentially regulated over time by abiotic stresses, including drought and salinity, as well as after methyl jasmonate treatments.…”

“…Furthermore, this report indicates that CsAMTs expression in tea leaves is differentially regulated over time by abiotic stresses, including drought and salinity, as well as after methyl jasmonate treatments. Under these treatments, specific CsAMTs genes were up-regulated or down-regulated in different ways, suggesting different functions to cope with various stresses ( Wang et al., 2022c ).…”

“…Also, Wang et al. ( Wang et al., 2022c ) found that 11 yeast transformant lines grew well on 0.3 mM NH 4 + as the sole N source, indicating their high affinity for NH 4 + permeation. The transcriptional regulation of CsAMTs differed even at the cultivar level ( Li et al., 2017 ).…”