A cross population between D. kaki and D. virginiana shows high variability for saline tolerance and improved salt stress tolerance

Abstract

Persimmon (Diospyros kaki Thunb.) production is facing important problems related to climate change in the Mediterranean areas. One of them is soil salinization caused by the decrease and change of the rainfall distribution. In this context, there is a need to develop cultivars adapted to the increasingly challenging soil conditions. In this study, a backcross between (D. kaki x D. virginiana) x D. kaki was conducted, to unravel the mechanism involved in salinity tolerance of persimmon. The backcross involved the two species most used as rootstock for persimmon production. Both species are clearly distinct in their level of tolerance to salinity. Variables related to growth, leaf gas exchange, leaf water relations and content of nutrients were significantly affected by saline stress in the backcross population.Water flow regulation appears as a mechanism of salt tolerance in persimmon via differences in water potential and transpiration rate, which reduces ion entrance in the plant. Genetic expression of eight putative orthologous genes involved in different mechanisms leading to salt tolerance was analyzed. Differences in expression levels among populations under saline or control treatment were found. The 'High affinity potassium transporter' (HKT1-like) reduced its expression levels in the roots in all studied populations. Results obtained allowed selection of tolerant rootstocks genotypes and describe the hypothesis about the mechanisms involved in salt tolerance in persimmon that will be useful for breeding salinity tolerant rootstocks. OPEN ACCESS Citation: Gil-Muñoz F, Pérez-Pérez JG, Quiñones A, Primo-Capella A, Cebolla J, Forner-Giner MÁ, et al. (2020) A cross population between D. kaki and D. virginiana shows high variability for saline tolerance and improved salt stress tolerance. PLoS ONE 15(2): e0229023. https://doi.org/10.increased by four times and production by near five [1]. Despite the recent and fast increase in persimmon production in the Mediterranean, the persimmon industry is facing important problems related to climate change. One of them is the soil salinization caused by the decrease and change of the rainfall distribution, which is causing an increase of salts in the irrigation water [2]. In order to keep the production in these areas, availability of rootstocks tolerant to salinity is required [3].The most commonly used rootstocks for persimmon production in these areas are seedlings from Diospyros lotus species, because of its tolerance to lime-filled soils and its adaptability to the Mediterranean conditions. Furthermore, D. lotus has a root system that does not produce basal shoots [4], facilitating the management of the orchards. However, this species is highly sensitive to salinity [5,6]. Other species used as rootstocks in some countries is Diospyros virginiana. This species is tolerant to salinity and performs well on lime-filled soils, but confers too much vigor to the plant, and produces many basal shoots, thus hindering crop management [7,8]. The most used rootstock around th...

Biotechnological tools applied to the improvement of persimmon (Diospyros kaki Thunb) culture.

“…The mechanism of tolerance to osmotic stress found was based in the water use efficiency (WUE). BC tolerant population has shown to have better tolerance to saline stress than sensitive BC through a higher WUE, which agrees with previous results on Diospyrus genus (Gil- Muñoz et al, 2020). Since the lack of variability for this character in the DV and DK populations, we can conclude the variability into BC has been generated through crossing.…”

“…Sample pre-treatments were performed as described in Gil-Muñoz et al (2020). Na + , Ca 2+ , K + , Mg 2+ , P and S content was determined (mg g -1 dry w.t.)…”

“…The CIPK genes from wild barley and maize are also known to be implicated in salt tolerance responses (Li et al, 2012;Chen et al, 2014). Furthermore, in tolerant persimmon species such as Diospyros virginiana, salt stress tolerance is believed to be caused by a high affinity potassium transporter HKT-1-like gene in roots (Gil-Muñoz et al, 2020), which was previously described in other species as key factor in salinity tolerance (Garciadeblás et al, 2003;Huang et al, 2006;Horie et al, 2007;Almeida et al, 2013).…”

Transcriptomic Analysis Reveals Salt Tolerance Mechanisms Present in Date-Plum Persimmon Rootstock (Diospyros Lotus)

“…The photosynthetically active radiation (PAR) was adjusted to 1.000 µmol m -2 s -1 photon ux density and the air ow rate through the cuvette was 0.5- After saline treatment, three leaves from each plant were collected. Sample pre-treatments were performed as described previously (38). Na + , Ca 2+ , K + , Mg 2+ , P and S content was determined using a multiple-collector inductively coupled plasma mass spectrometry (MC-ICP MS, Thermo Finnigan Neptune).…”

“…The CIPK genes from wild barley and maize are also known to be implicated in salt tolerance responses (36,37). Furthermore, in tolerant persimmon species such as Diospyros virginiana, salt stress tolerance is believed to be caused by a high a nity potassium transporter HKT-1-like gene in roots (38), which was previously described in other species as key factor in salinity tolerance (39)(40)(41)(42). Although Na + ion translocation and regulation mechanisms have previously been reported in several species, little is known about Cl − transport and regulation.…”