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Increased drought tolerance in plants engineered for low lignin and low xylan content

Increased drought tolerance in plants engineered for low lignin and low xylan content

Authors :
Aymerick Eudes
Dominique Loque
Jingwei Yan
Edward E. K. Baidoo
Aying Zhang
Aude Aznar
Devon Birdseye
Patrick M. Shih
Henrik Vibe Scheller
Camille Chalvin
Source :
Biotechnology for Biofuels, Biotechnology for Biofuels, Vol 11, Iss 1, Pp 1-11 (2018), Yan, J; Aznar, A; Chalvin, C; Birdseye, DS; Baidoo, EEK; Eudes, A; et al.(2018). Increased drought tolerance in plants engineered for low lignin and low xylan content. Biotechnology for Biofuels, 11(1). doi: 10.1186/s13068-018-1196-7. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/2tr6q2t7
Publication Year :
2018
Publisher :
Springer Science and Business Media LLC, 2018.

Abstract

Background We previously developed several strategies to engineer plants to produce cost-efficient biofuels from plant biomass. Engineered Arabidopsis plants with low xylan and lignin content showed normal growth and improved saccharification efficiency under standard growth conditions. However, it remains to be determined whether these engineered plants perform well under drought stress, which is the primary source of abiotic stress in the field. Results Upon exposing engineered Arabidopsis plants to severe drought, we observed better survival rates in those with a low degree of xylan acetylation, low lignin, and low xylan content compared to those in wild-type plants. Increased pectic galactan content had no effect on drought tolerance. The drought-tolerant plants exhibited low water loss from leaves, and drought-responsive genes (RD29A, RD29B, DREB2A) were generally up-regulated under drought stress, which did not occur in the well-watered state. When compared with the wild type, plants with low lignin due to expression of QsuB, a 3-dehydroshikimate dehydratase, showed a stronger response to abscisic acid (ABA) in assays for seed germination and stomatal closure. The low-lignin plants also accumulated more ABA in response to drought than the wild-type plants. On the contrary, the drought tolerance in the engineered plants with low xylan content and low xylan acetylation was not associated with differences in ABA content or response compared to the wild type. Surprisingly, we found a significant increase in galactose levels and sugar released from the low xylan-engineered plants under drought stress. Conclusions This study shows that plants engineered to accumulate less lignin or xylan are more tolerant to drought and activate drought responses faster than control plants. This is an important finding because it demonstrates that modification of secondary cell walls does not necessarily render the plants less robust in the environment, and it shows that substantial changes in biomass composition can be achieved without compromising plant resilience. Electronic supplementary material The online version of this article (10.1186/s13068-018-1196-7) contains supplementary material, which is available to authorized users.

Details

ISSN :
17546834
Volume :
11
Database :
OpenAIRE
Journal :
Biotechnology for Biofuels
Accession number :
edsair.doi.dedup.....005692aa23b973ec8e0dfe4e5f18b26e
Full Text :
https://doi.org/10.1186/s13068-018-1196-7