Plant-Mediated Effects of Water Deficit on the Performance of Tetranychus evansi on Tomato Drought-Adapted Accessions

Abstract

Climate change is expected to increase drought periods and the performance and dispersal of some invasive species such as Tetranychus evansi, which has been reported to take advantage of the nutritional changes induced by water-shortage on the tomato cultivar Moneymaker (MM). We have examined the implications for mite’s biology of four accessions of the drought-adapted tomatoes, “Tomàtiga de Ramellet” (TR), under moderate drought stress. Mite performance was enhanced by drought in two accessions (TR61 and TR154), but not in the other two accessions (TR58 and TR126). We selected one accession of each outcome (i.e., TR154 and TR126) to further analyze plant nutritional parameters. We found that free sugars and most essential amino acids for mites were induced by drought and/or mite infestation on MM and TR154 plants, whereas sugars were not altered and a reduced number of essential amino acids were induced by drought in TR126. Remarkably, mite performance was enhanced by leaf infiltration of free sugars, essential amino acids mixture, and L-proline on well-watered MM and by free sugars on drought-stressed TR126 plants. These results indicate a positive link between the induction of soluble carbohydrates and amino acids used by the plant for osmotic adjustment and mite performance. The effects of drought and/or mite infestation on the defense response of plants was analyzed at three levels: phytohormone accumulation, the transcript levels of marker genes linked to jasmonates (JAs), salicylic acid (SA), and abscisic acid (ABA) pathways, and the activity of defense proteins. The ability of T. evansi to downregulate the accumulation of defense-related phytohormones was noted on MM and the two TR accessions analyzed (TR126 and TR154), though differences in the induction of protein defense genes and activities by drought and/or mite infestation were observed among them. These results emphasize the importance of studying plant biotic and abiotic stress factors in combination and provides an experimental framework for screening drought-tolerant tomato accessions that will be also resistant to herbivore mites.

Mediterranean Long Shelf-Life Landraces: An Untapped Genetic Resource for Tomato Improvement

“…In this regard, consumers appreciate that the skin, which is thick and hard, remains completely free of pericarp after spreading, which is uncommon in diverse Iberian Peninsula LSL landraces, and especially in commercialized 'de Ramellet'-like F 1 hybrids. Some landraces have proven to be tolerant to pests (Ximénez-Embún et al, 2018).…”

Early Molecular Responses of Tomato to Combined Moderate Water Stress and Tomato Red Spider Mite Tetranychus evansi Attack

“…However, this interaction has been shown to be more complex since it also depends on the plant species, the intensity and duration of the drought stress and the arthropod feeding mechanism [ 30 , 31 ]. Previous results coming from the analysis of the interaction between T. urticae or T. evansi and moderate water stress conditions in tomato plants (cv Moneymaker) showed the increase of both spider mite populations, thus confirming the modification of the plant–spider mite interaction under water stress conditions [ 21 , 32 , 33 ]. Moreover, the characterization of the T. evansi attack to traditional drought-tolerant tomato varieties has shown that adaptation of tomato plants to moderate drought modifies physiological plant responses to tomato red spider mite associated with an increase of tomato ABA levels [ 21 ].…”

“…Previous results coming from the analysis of the interaction between T. urticae or T. evansi and moderate water stress conditions in tomato plants (cv Moneymaker) showed the increase of both spider mite populations, thus confirming the modification of the plant–spider mite interaction under water stress conditions [ 21 , 32 , 33 ]. Moreover, the characterization of the T. evansi attack to traditional drought-tolerant tomato varieties has shown that adaptation of tomato plants to moderate drought modifies physiological plant responses to tomato red spider mite associated with an increase of tomato ABA levels [ 21 ]. All these previous results indicate that plant response mechanisms boosting T. evansi growth under drought stress conditions and those by which it supresses plant defences might be independent, and that ABA is involved in the fine-tune of spider mite-mediated plant defences [ 21 , 32 ].…”

“…Proteomics and metabolomics studies have identified putative protein effectors coming from mite feeding that may be recognized by the plant defence system to initiate a successful plant defence response or in other cases, used by the spider mite to interfere and supress the plant defence system. Several pioneering works identified (i) two salivary proteins named as effectors 28 and 84, which are present in T. urticae and T. evansi , have been involved in suppression of JA and SA-dependent responses, (ii) a family of mite secreted salivary proteins referred as SHOT, which are produced depending of the host identity, and (iii) two secreted proteins named tetranins which could upregulated plant defences [ 14 , 18 , 19 , 20 , 21 ]. Moreover, spider mites may induce defence responses in systemic leaves and some strains and species of mites as T. evansi are able to suppress or reduce tomato defence responses [ 17 , 22 , 23 ], uncovering the complexity of the plant–spider mite interaction.…”

“…Moreover, the characterization of the T. evansi attack to traditional drought-tolerant tomato varieties has shown that adaptation of tomato plants to moderate drought modifies physiological plant responses to tomato red spider mite associated with an increase of tomato ABA levels [ 21 ]. All these previous results indicate that plant response mechanisms boosting T. evansi growth under drought stress conditions and those by which it supresses plant defences might be independent, and that ABA is involved in the fine-tune of spider mite-mediated plant defences [ 21 , 32 ].…”