TY - JOUR
T1 - Comparative transcriptomic and metabolic analysis of wild and domesticated wheat genotypes reveals differences in chemical and physical defense responses against aphids
AU - Batyrshina, Zhaniya S.
AU - Yaakov, Beery
AU - Shavit, Reut
AU - Singh, Anuradha
AU - Tzin, Vered
N1 - Funding Information:
This research was supported by the Binational Agricultural Research and Development Fund (BARD grant number IS-5092-18R). The funders had no role in the study design, data collection, and analysis, decision to publish, or preparation of the manuscript.
Publisher Copyright:
© 2020 The Author(s).
PY - 2020/1/13
Y1 - 2020/1/13
N2 - Background: Young wheat plants are continuously exposed to herbivorous insect attack. To reduce insect damage and maintain their growth, plants evolved different defense mechanisms, including the biosynthesis of deterrent compounds named benzoxazinoids, and/or trichome formation that provides physical barriers. It is unclear whether both of these mechanisms are equally critical in providing an efficient defense for wheat seedlings against aphids- A n economically costly pest in cereal production. Results: In this study, we compared the transcriptome, metabolome, benzoxazinoids, and trichome density of three selected wheat genotypes, with a focus on differences related to defense mechanisms. We chose diverse wheat genotypes: Two tetraploid wheat genotypes, domesticated durum 'Svevo' and wild emmer 'Zavitan,' and one hexaploid bread wheat, 'Chinese Spring.' The full transcriptomic analysis revealed a major difference between the three genotypes, while the clustering of significantly different genes suggested a higher similarity between the two domesticated wheats than between either and the wild wheat. A pathway enrichment analysis indicated that the genes associated with primary metabolism, as well as the pathways associated with defense such as phytohormones and specialized metabolites, were different between the three genotypes. Measurement of benzoxazinoid levels at the three time points (11, 15, and 18 days after germination) revealed high levels in the two domesticated genotypes, while in wild emmer wheat, they were below detection level. In contrast to the benzoxazinoid levels, the trichome density was dramatically higher in the wild emmer than in the domesticated wheat. Lastly, we tested the bird cherry-oat aphid's (Rhopalosiphum padi) performance and found that Chinese Spring is more resistant than the tetraploid genotypes. Conclusions: Our results show that benzoxazinoids play a more significant defensive role than trichomes. Differences between the abundance of defense mechanisms in the wild and domesticated plants were observed in which wild emmer possesses high physical defenses while the domesticated wheat genotypes have high chemical defenses. These findings provide new insights into the defense adaptations of wheat plants against aphids.
AB - Background: Young wheat plants are continuously exposed to herbivorous insect attack. To reduce insect damage and maintain their growth, plants evolved different defense mechanisms, including the biosynthesis of deterrent compounds named benzoxazinoids, and/or trichome formation that provides physical barriers. It is unclear whether both of these mechanisms are equally critical in providing an efficient defense for wheat seedlings against aphids- A n economically costly pest in cereal production. Results: In this study, we compared the transcriptome, metabolome, benzoxazinoids, and trichome density of three selected wheat genotypes, with a focus on differences related to defense mechanisms. We chose diverse wheat genotypes: Two tetraploid wheat genotypes, domesticated durum 'Svevo' and wild emmer 'Zavitan,' and one hexaploid bread wheat, 'Chinese Spring.' The full transcriptomic analysis revealed a major difference between the three genotypes, while the clustering of significantly different genes suggested a higher similarity between the two domesticated wheats than between either and the wild wheat. A pathway enrichment analysis indicated that the genes associated with primary metabolism, as well as the pathways associated with defense such as phytohormones and specialized metabolites, were different between the three genotypes. Measurement of benzoxazinoid levels at the three time points (11, 15, and 18 days after germination) revealed high levels in the two domesticated genotypes, while in wild emmer wheat, they were below detection level. In contrast to the benzoxazinoid levels, the trichome density was dramatically higher in the wild emmer than in the domesticated wheat. Lastly, we tested the bird cherry-oat aphid's (Rhopalosiphum padi) performance and found that Chinese Spring is more resistant than the tetraploid genotypes. Conclusions: Our results show that benzoxazinoids play a more significant defensive role than trichomes. Differences between the abundance of defense mechanisms in the wild and domesticated plants were observed in which wild emmer possesses high physical defenses while the domesticated wheat genotypes have high chemical defenses. These findings provide new insights into the defense adaptations of wheat plants against aphids.
KW - Aphid infestation
KW - Benzoxazinoids
KW - Defense
KW - Domestication
KW - Rhopalosiphum padi
KW - Trichome
KW - Triticum aestivum
KW - Triticum turgidum
KW - Wheat
UR - http://www.scopus.com/inward/record.url?scp=85077785997&partnerID=8YFLogxK
U2 - 10.1186/s12870-019-2214-z
DO - 10.1186/s12870-019-2214-z
M3 - Article
C2 - 31931716
AN - SCOPUS:85077785997
SN - 1471-2229
VL - 20
JO - BMC Plant Biology
JF - BMC Plant Biology
IS - 1
M1 - 19
ER -