title: The abiotic stress-responsive NAC-type transcription factor SlNAC4 regulates salt and drought tolerance and stress-related genes in tomato (Solanum lycopersicum).
abstract: SlNAC4 functions as a stress-responsive transcription factor and might be useful for crop salt and drought tolerance improvement. Abiotic stresses, especially salinity and drought, are major factors that significantly limit crop growth and productivity. Plant-specific NAC transcription factors play crucial roles in various stress responses. However, to date only little information regarding stress-related NAC genes is available in tomato. Previously, we reported that tomato SlNAC4-SlNAC10 genes are involved in response of various abiotic stresses. Expression analysis revealed that SlNAC4 was also induced significantly by MeJA, but not by ABA. To further unravel the function of SlNAC4 in response to abiotic stress, we investigated the effects of salt and drought stress on wild-type and SlNAC4-RNAi transgenic tomato plants. The results demonstrated that the root and shoot growth of RNAi plants was more inhibited by salt stress than that of wild-type at post-germination stage. The leaf salt assay also showed less tolerance in transgenic plants by retaining lower chlorophyll content compared with wild-type plants. In addition, transgenic plants became less tolerant to salt and drought stress in soil, which were demonstrated by lower levels of water and chlorophyll contents, and higher water loss rate in their leaves as compared to wild-type plants under stressed conditions. Notably, the expressions of multiple stress-related genes were downregulated in SlNAC4-RNAi plants under both control and salt-stressed conditions. Collectively, these results highlight the important role of SlNAC4 functions as a stress-responsive transcription factor in positive modulation of abiotic stress tolerance through an ABA-independent signaling networks and possibly in response to biotic stress, and may hold promising applications in the engineering of salt- and drought-tolerant tomato.
authors: Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Room 313, Bioengineering College, Chongqing University, Campus A, 174 Shapingba Main Street, Chongqing, 400044, People's Republic of China, mingkuzhu007@126.com.
authors: Mingku
authors: M
authors: Zhu
authors: Guoping
authors: G
authors: Chen
authors: Jianling
authors: J
authors: Zhang
authors: Yanjie
authors: Y
authors: Zhang
authors: Qiaoli
authors: Q
authors: Xie
authors: Zhiping
authors: Z
authors: Zhao
authors: Yu
authors: Y
authors: Pan
authors: Zongli
authors: Z
authors: Hu
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000085:Acetates / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000235:genetics*; D003517:Cyclopentanes / Q000494:pharmacology; D055864:Droughts; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics*; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins / Q000494:pharmacology; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012965:Sodium Chloride / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D034741:RNA, Small Interfering; D014157:Transcription Factors; D012965:Sodium Chloride; D000040:Abscisic Acid; C072239:methyl jasmonate