Expression of the citrus CsTIP2;1 gene improves tobacco plant growth, antioxidant capacity and physiological adaptation under stress conditions

Abstract

Overexpression of the citrus CsTIP2;1 improves plant growth and tolerance to salt and drought stresses by enhancing cell expansion, H O detoxification and stomatal conductance. Tonoplast intrinsic proteins (TIPs) are a subfamily of aquaporins, belonging to the major intrinsic protein family. In a previous study, we have shown that a citrus TIP isoform, CsTIP2;1, is highly expressed in leaves and also transcriptionally regulated in leaves and roots by salt and drought stresses and infection by 'Candidatus Liberibacter asiaticus', the causal agent of the Huanglongbing disease, suggesting its involvement in the regulation of the flow of water and nutrients required during both normal growth and stress conditions. Here, we show that the overexpression of CsTIP2;1 in transgenic tobacco increases plant growth under optimal and water- and salt-stress conditions and also significantly improves the leaf water and oxidative status, photosynthetic capacity, transpiration rate and water use efficiency of plants subjected to a progressive soil drying. These results correlated with the enhanced mesophyll cell expansion, midrib aquiferous parenchyma abundance, HO detoxification and stomatal conductance observed in the transgenic plants. Taken together, our results indicate that CsTIP2;1 plays an active role in regulating the water and oxidative status required for plant growth and adaptation to stressful environmental conditions and may be potentially useful for engineering stress tolerance in citrus and other crop plants.

Genome-wide characterization and expression analysis of citrus NUCLEAR FACTOR-Y (NF-Y) transcription factors identified a novel NF-YA gene involved in drought-stress response and tolerance

“…Havana used in Agrobacterium -mediated genetic transformation experiments, were derived from pre-established cultures kept in the Tissue Culture Laboratory of the Center for Biotechnology and Genetics (CBG) of the State University of Santa Cruz (UESC). The stress tolerance of wild-type (WT) and transgenic tobacco plants was examined by the leaf-disc dehydration tolerance assay, in vitro drought stress tolerance assay and soil dry-down experiment under greenhouse conditions, as previously described [ 38 ]. In brief, uniform samples of leaf discs were extracted from mature, fully expanded leaves of adult plants of WT and transgenic (T 0 generation) tobacco kept in a greenhouse; this was done with the aid of a 1-cm diameter punch, avoiding the region of the central vein.…”

“…The rate of dehydration was determined as the percentage of FW loss versus the initial fresh weight. At the end of the dehydration assays (180 min), leaf discs were subjected to histochemical detection of H 2 O 2 according to the previously described methodology [ 38 ]. For the in vitro drought stress tolerance assay, seven-day-old WT and transgenic (T 2 generation) seedlings were removed from Murashige and Skoog (MS) germination medium for the WT and MS medium + 50 mg L -1 kanamycin (Sigma, St. Louis, MO, USA) for the transgenic lines and transferred to MS medium only (control treatment) or MS medium containing 15% polyethylene glycol 6000 (PEG-6000) (Merck, Darmstadt, Germany).…”

“…Each WT and transgenic line was represented by five biological replicates per treatment, obtained through micropropagation. The physiological analyzes, including the net CO 2 assimilation rate ( A ), stomatal conductance to water vapor ( gs ) and the leaf transpiration rate ( E ) were performed in the morning (08:00–09:00 AM) using a portable photosynthesis system LI-6400 (Li-Cor) equipped with an artificial light resource (6400-02B RedBlue), as previously described [ 38 ].…”

The Tonoplast Intrinsic Protein Gene KvTIP3 is Responsive to Different Abiotic Stresses in Kosteletzkya virginica

“…In Mesembryanthemum crystallinum, osmotic stress can induce the relocation of McTIP1;2 from the tonoplast to other membranes [24]. Consistently, expression of CsTIP2;1 from citrus in tobacco improved the growth and antioxidant capacity of transgenic plants under stress conditions [25]. Similarly, expression of tomato SlTIP2;2 and jojoba ScPIP1 enhanced the tolerance of transgenic plants to various abiotic stresses [26].…”

Methyl Jasmonate Affects Photosynthesis Efficiency, Expression of HvTIP Genes and Nitrogen Homeostasis in Barley

“…Such a location was detected for TIP1;1, TIP1;2 and TIP2;1 in Arabidopsis [ 70 , 71 , 72 ]. It was also shown that overexpression of citrus ( Citrus limonia ) gene CsTIP2;1 in transgenic tobacco ( Nicotiana tabacum ) led to improvement of photosynthetic capacity under drought stress [ 73 ].…”