# Transcriptional analyses of root responses under soil water stress of one-year old apple cultivars

Lamia Krichen, Baptiste Guitton, Jean-Jacques Kelner, Evelyne Costes

► To cite this version:

Lamia Krichen, Baptiste Guitton, Jean-Jacques Kelner, Evelyne Costes. Transcriptional analyses of root responses under soil water stress of one-year old apple cultivars. 8. International Rosaceae Genomics Conference (RGC8), Jun 2016, Angers, France., 2016. [hal-01606193](https://hal.science/hal-01606193)

HAL Id: hal-01606193

https://hal.science/hal-01606193

Submitted on 3 Jun 2020

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution - ShareAlike 4.0 International License
<figure><img src="image_2.png" /></figure>

# Transcriptional analyses of root responses under soil water stress of one-year old apple cultivars

S503

Lamia Krichen<fnref n="1" />,<fnref n="2" />, Baptiste Guitton<fnref n="1" />, Jean Jacques Kelner<fnref n="3" />, Evelyne Costes<fnref n="1" />

Global climate change may lead to longer or more frequent episodes of extreme temperatures and drought, thus threatening plant crops. Thus, we focused on apple tree aiming to identify the molecular mechanisms that are triggered when trees face water soil deficit. We focused on differentially expressed transcripts (DET) in roots, between well-watered trees compared to trees grown under soil water deficit either moderate (MS) and severe (SS).

Two apple cultivars, 'Starkrimson' (ST) and 'Granny Smith' (GS), with contrasted behavior under water deficit, were grafted on M9 rootstock and grown in pots under controlled conditions. Roots were sampled when transpirable soil water (FTSW)=0.5 and FTSW=0.2 were reached, for MS and SS stress, respectively. RNA was extracted and analyzed using the AryANE micro-array apple chip to identify DET response to moderate and severe soil water deprivation. Among DET in roots, 209 up and 137 down-regulated genes were common to both cultivars under MS while 148 up and 542 down-regulated genes were common to both cultivars under SS. DET linked to the response to osmotic stress were observed at MS, especially signal sensors proteins kinases and phosphatases which were up-regulated. As expected, DET related to abscissic acid (ABA) were highly expressed under water deficit conditions, both ABA-dependent (ADP) and ABA-independent pathways (AIP) being stimulated. ABA biosynthesis was activated in both genotypes in MS, even though to a lesser extent in ST than in GS. However, these transcripts were no more differentially expressed in SS, suggesting that other mechanisms are involved under SS.

Specific DET to each genotype were also observed. ST had a higher number of upregulated DET at MS and downregulated DET at SS than GS. Such results prove that even when grafted on the same rootstock, we notice a significant difference on the ST and GS roots system response to the soil water deficit evidencing that root systems (here M9) response to the soil water deficit depends on the grafted scion, probably because of different transpiration and regulation in response to soil water deprivation of the two scion genotypes. Further analyses are currently performed to decipher DET in aerial organs.

**Keywords** : differentially expressed transcript, gene expression, gene function, Malus x domestica, moderate and severe water deficit, hormonal signaling, osmotic regulation.

<footnote n="1">¹INRA, UMR AGAP (Amélioration Génétique et Adaptation des Plantes) - AFEF (Architecture et Fonctionnement des Espèces Fruitières), INRA-CIRAD-SupAgro Montpellier, France</footnote>

<footnote n="2">²Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie. Faculté des Sciences de Tunis, Université de Tunis-El Manar (UTM), Tunisia</footnote>

<footnote n="3">³Montpellier SupAgro, UMR AGAP (Amélioration Génétique et Adaptation des Plantes) - AFEF (Architecture et Fonctionnement des Espèces Fruitières, INRA-CIRAD-SupAgro Montpellier, France</footnote>