Effects of heat stress in the leaf mitotic cell cycle and chromosomes of four wine-producing grapevine varieties

Abstract

Grapevine varieties respond differentially to heat stress (HS). HS ultimately reduces the photosynthesis and respiratory performance. However, the HS effects in the leaf nuclei and mitotic cells of grapevine are barely known. This work intends to evaluate the HS effects in the leaf mitotic cell cycle and chromosomes of four wine-producing varieties: Touriga Franca (TF), Touriga Nacional (TN), Rabigato, and Viosinho. In vitro plants with 11 months were used in a stepwise acclimation and recovery (SAR) experimental setup comprising different phases: heat acclimation period (3 h-32 °C), extreme HS (1 h-42 °C), and two recovery periods (3 h-32 °C and 24 h-25 °C), and compared to control plants (maintained in vitro at 25 °C). At the end of each SAR phase, leaves were collected, fixed, and used for cell suspensions and chromosome preparations. Normal and abnormal interphase and mitotic cells were observed, scored, and statistically analyzed in all varieties and treatments (control and SAR phases). Different types of chromosomal anomalies in all mitotic phases, treatments, and varieties were found. In all varieties, the percentage of dividing cells with anomalies (%DCA) after extreme HS increased relative to control. TF and Viosinho were considered the most tolerant to HS. TF showed a gradual MI reduction from heat acclimation to HS and the lowest %DCA after HS and 24 h of recovery. Only Viosinho reached the control values after the long recovery period. Extrapolating these data to the field, we hypothesize that during consecutive hot summer days, the grapevine plants will not have time or capacity to recover from the mitotic anomalies caused by high temperatures.

Heat stress tolerance assayed in four wine-producing grapevine varieties using a cytogenetic approach

“…The significant increase in the number of prophase cells was also detected in the mesophyll cells of the same grapevine varieties after exposure to HS and also in control plants . Nevertheless, in this work, the average values of both normal and irregular prophases were higher than those reported by Carvalho et al (2018) in the mesophyll cells. The increase of prophase cells upon different abiotic stresses was previously described in wheat (Pekol et al, 2016;Reis et al, 2018).…”

“…The dividing cells presented anomalies such as chromatin stickiness in prophase and telophase ( Fig. 1d and l) which is highly frequent through the mitotic cycle of cells exposed to different abiotic stresses, including HS (Pekol et al, 2016;Carvalho et al, 2018;Reis et al, 2018). C-metaphases (Fig.…”

“…One suitable long-term strategy to mitigate the negative consequences of high temperatures in viticulture will be the genetic improvement towards the selection of grapevine varieties more tolerant to HS. Cytogenetics is an important tool of plant genetic breeding, and it could be helpful in the selection of grapevine genotypes with that purpose (Pereira et al, 2014;Carvalho et al, 2018).…”

Interactive effect of thiourea application on morphological and physiological characteristics in Cicer arietinum L. grown at different temperatures

“…Similar to cold stress, heat stress elongates the cell cycle and decreases cell division. This may be the reason for the decrease in morphological parameters in plants exposed to heat stress (Carvalho et al, 2018).…”

Automated Imaging, Tracking, and Analytics Pipeline for Differentiating Environmental Effects on Root Meristematic Cell Division

“…While these stress response studies have shed light on many physiological and molecular effects, iron deficiency stress and heat stress responses have been traditionally studied in isolation. Given that, in field conditions, it is common for plants to experience stresses in combination rather than as isolated stress events (Thimm et al, 2001; Suzuki et al, 2014; Corrales et al, 2017; Carvalho et al, 2018), it is necessary to understand the existence of any interplay between stress response pathways when plants are exposed to multiple stresses. Experimental and computational tools that extract spatial and temporal similarities/differences in the molecular response of plants under both combinatorial and individual stresses would provide insight into the existence of interplay between two stress response pathways.…”