The Greater Phenotypic Homeostasis of the AllopolyploidCoffea arabicaImproved the Transcriptional Homeostasis Over that of Both Diploid Parents

Abstract

Polyploidy impacts the diversity of plant species, giving rise to novel phenotypes and leading to ecological diversification. In order to observe adaptive and evolutionary capacities of polyploids, we compared the growth, primary metabolism and transcriptomic expression level in the leaves of the newly formed allotetraploid Coffea arabica species compared with its two diploid parental species (Coffea eugenioides and Coffea canephora), exposed to four thermal regimes (TRs; 18–14, 23–19, 28–24 and 33–29°C). The growth rate of the allopolyploid C. arabica was similar to that of C. canephora under the hottest TR and that of C. eugenioides under the coldest TR. For metabolite contents measured at the hottest TR, the allopolyploid showed similar behavior to C. canephora, the parent which tolerates higher growth temperatures in the natural environment. However, at the coldest TR, the allopolyploid displayed higher sucrose, raffinose and ABA contents than those of its two parents and similar linolenic acid leaf composition and Chl content to those of C. eugenioides. At the gene expression level, few differences between the allopolyploid and its parents were observed for studied genes linked to photosynthesis, respiration and the circadian clock, whereas genes linked to redox activity showed a greater capacity of the allopolyploid for homeostasis. Finally, we found that the overall transcriptional response to TRs of the allopolyploid was more homeostatic compared with its parents. This better transcriptional homeostasis of the allopolyploid C. arabica afforded a greater phenotypic homeostasis when faced with environments that are unsuited to the diploid parental species.

Elevated temperatures impose transcriptional constraints on coffee genotypes and elicit intraspecific differences in thermoregulation

“…1 and 379 Table S1). The present findings are in agreement with recent studies that describe 380 photosynthetic stability, as well as thermoregulatory differences, between coffee 381 genotypes in response to increased growth temperatures (Bertrand et al, 2015;Martins 382 et al, 2016, DaMatta et al, 2019. Comparative studies identifying warm tolerant 383 coffee genotypes are scarce and our results show that, based on the established 384 experimental conditions, cv.…”

“…4). These negative correlations 460 between sugar content and temperature stress are in agreement with the report for C. 461 arabica L. by Bertrand et al (2015), and reinforces our conclusion that warmer 462 temperature has a genetic and physiologic impact on coffee leaves in a genotype-463 dependent manner. Coffee is a worldwide commodity, produced in over 80 countries and 467 foundational to the economy of many regions through employment and trade (DaMatta 468 and Ramalho, 2006).…”

“…However, other regulatory genes such as Glucose-1-phosphate 337 adenyltransferase (Cc02_17340) was only observed up-regulated in cv. Acauã whereas results comparing different coffee species (Bertrand et al, 2015). Warmer temperature affects sugar and protein content of coffee genotypes 344 Based on previous results from transcriptional analyses, we investigated 345 whether warmer growth temperatures could affect the sugar content in a genotype-346 dependent manner (Fig.…”

Transcriptome Analysis of Leaves, Flowers and Fruits Perisperm of Coffea arabica L. Reveals the Differential Expression of Genes Involved in Raffinose Biosynthesis

“…arabica transcriptome gene atlas for flowers and perisperm during the initial development of fruits using RNA-seq. Most transcriptome studies on coffee have focused on the mature fruit at the last maturation stage, when they are ready to be collected and processed [4–6], or on leaves [8]. However, most chemical compounds of coffee grain are produced at the beginning of fruit development, when the perisperm is the predominant tissue.…”

“…canephora , was recently published [3]. Coffee transcriptome studies have been perfomed [4–8] but so far, very few data is available for C . arabica flower and fruit development.…”