Work

NtLTP4, a lipid transfer protein that enhances salt and drought stresses tolerance in Nicotiana tabacum

Year: 2018

Type: article

Abstract: Lipid transfer proteins (LTPs), a class of small, ubiquitous proteins, play critical roles in various environmental stresses. However, their precise biological functions remain unknown. Here we isolated an extracellular matrix-localised LTP, NtLTP4, from Nicotiana tabacum . The overexpression of NtLTP4 in N . tabacum enhanced resistance to salt and drought stresses. Upon exposure to high salinity, NtLTP4 -overexpressing lines (OE lines) accumulated low Na + levels. Salt-responsive genes, including Na + /H + exchangers ( NHX1 ) and high-affinity K + transporter1 ( HKT1 ), were dramatically higher in OE lines than in wild-type lines. NtLTP4 might regulate transcription levels of NHX1 and HKT1 to alleviate the toxicity of Na + . Interestingly, OE lines enhanced the tolerance of N . tabacum to drought stress by reducing the transpiration rate. Moreover, NtLTP4 could increase reactive oxygen species (ROS)-scavenging enzyme activity and expression levels to scavenge excess ROS under drought and high salinity conditions. We used a two-hybrid yeast system and screened seven putative proteins that interact with NtLTP4 in tobacco. An MAPK member, wound-induced protein kinase, was confirmed to interact with NtLTP4 via co-immunoprecipitation and a firefly luciferase complementation imaging assay. Taken together, this is the first functional analysis of NtLTP4 , and proves that NtLTP4 positively regulates salt and drought stresses in N . tabacum .

Source: Scientific Reports

DOI: 10.1038/s41598-018-27274-8