TY - JOUR A1 - Allu, Annapurna Devi A1 - Soja, Aleksandra Maria A1 - Wu, Anhui A1 - Szymanski, Jedrzej A1 - Balazadeh, Salma T1 - Salt stress and senescence: identification of cross-talk regulatory components JF - Journal of experimental botany N2 - Leaf senescence is an active process with a pivotal impact on plant productivity. It results from extensive signalling cross-talk coordinating environmental factors with intrinsic age-related mechanisms. Although many studies have shown that leaf senescence is affected by a range of external parameters, knowledge about the regulatory systems that govern the interplay between developmental programmes and environmental stress is still vague. Salinity is one of the most important environmental stresses that promote leaf senescence and thus affect crop yield. Improving salt tolerance by avoiding or delaying senescence under stress will therefore play an important role in maintaining high agricultural productivity. Experimental evidence suggests that hydrogen peroxide (H2O2) functions as a common signalling molecule in both developmental and salt-induced leaf senescence. In this study, microarray-based gene expression profiling on Arabidopsis thaliana plants subjected to long-term salinity stress to induce leaf senescence was performed, together with co-expression network analysis for H2O2-responsive genes that are mutually up-regulated by salt induced-and developmental leaf senescence. Promoter analysis of tightly co-expressed genes led to the identification of seven cis-regulatory motifs, three of which were known previously, namely CACGTGT and AAGTCAA, which are associated with reactive oxygen species (ROS)-responsive genes, and CCGCGT, described as a stress-responsive regulatory motif, while the others, namely ACGCGGT, AGCMGNC, GMCACGT, and TCSTYGACG were not characterized previously. These motifs are proposed to be novel elements involved in the H2O2-mediated control of gene expression during salinity stress-triggered and developmental senescence, acting through upstream transcription factors that bind to these sites. KW - Arabidopsis KW - hydrogen peroxide KW - longevity KW - reactive oxygen species KW - salt stress KW - senescence KW - signal cross-talk KW - transcription factor Y1 - 2014 U6 - https://doi.org/10.1093/jxb/eru173 SN - 0022-0957 SN - 1460-2431 VL - 65 IS - 14 SP - 3993 EP - 4008 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Devkar, Vikas A1 - Thirumalaikumar, Venkatesh P. A1 - Xue, Gang-Ping A1 - Vallarino, Jose G. A1 - Tureckova, Veronika A1 - Strnad, Miroslav A1 - Fernie, Alisdair R. A1 - Hoefgen, Rainer A1 - Mueller-Roeber, Bernd A1 - Balazadeh, Salma T1 - Multifaceted regulatory function of tomato SlTAF1 in the response to salinity stress JF - New phytologist : international journal of plant science N2 - Salinity stress limits plant growth and has a major impact on agricultural productivity. Here, we identify NAC transcription factor SlTAF1 as a regulator of salt tolerance in cultivated tomato (Solanum lycopersicum). While overexpression of SlTAF1 improves salinity tolerance compared with wild-type, lowering SlTAF1 expression causes stronger salinity-induced damage. Under salt stress, shoots of SlTAF1 knockdown plants accumulate more toxic Na+ ions, while SlTAF1 overexpressors accumulate less ions, in accordance with an altered expression of the Na+ transporter genes SlHKT1;1 and SlHKT1;2. Furthermore, stomatal conductance and pore area are increased in SlTAF1 knockdown plants during salinity stress, but decreased in SlTAF1 overexpressors. We identified stress-related transcription factor, abscisic acid metabolism and defence-related genes as potential direct targets of SlTAF1, correlating it with reactive oxygen species scavenging capacity and changes in hormonal response. Salinity-induced changes in tricarboxylic acid cycle intermediates and amino acids are more pronounced in SlTAF1 knockdown than wild-type plants, but less so in SlTAF1 overexpressors. The osmoprotectant proline accumulates more in SlTAF1 overexpressors than knockdown plants. In summary, SlTAF1 controls the tomato’s response to salinity stress by combating both osmotic stress and ion toxicity, highlighting this gene as a promising candidate for the future breeding of stress-tolerant crops. KW - abscisic acid (ABA) KW - ion homeostasis KW - NAC KW - proline KW - salt stress KW - SlTAF1 KW - transcription factors Y1 - 2019 U6 - https://doi.org/10.1111/nph.16247 SN - 0028-646X SN - 1469-8137 VL - 225 IS - 4 SP - 1681 EP - 1698 PB - Wiley CY - Hoboken ER -