Repository logo
 

C4 Photosynthesis in the Rice Paddy: Insights from the Noxious Weed Echinochloa glabrescens.


No Thumbnail Available

Type

Article

Change log

Authors

Covshoff, Sarah 
Szecowka, Marek 
Hughes, Thomas E 
Smith-Unna, Richard  ORCID logo  https://orcid.org/0000-0001-8721-7197
Kelly, Steven 

Abstract

The C4 pathway is a highly complex trait that increases photosynthetic efficiency in more than 60 plant lineages. Although the majority of C4 plants occupy disturbed, arid, and nutrient-poor habitats, some grow in high-nutrient, waterlogged conditions. One such example is Echinochloa glabrescens, which is an aggressive weed of rice paddies. We generated comprehensive transcriptome datasets for C4 E. glabrescens and C3 rice to identify genes associated with adaption to waterlogged, nutrient-replete conditions, but also used the data to better understand how C4 photosynthesis operates in these conditions. Leaves of E. glabrescens exhibited classical Kranz anatomy with lightly lobed mesophyll cells having low chloroplast coverage. As with rice and other hygrophytic C3 species, leaves of E. glabrescens accumulated a chloroplastic phosphoenolpyruvate carboxylase protein, albeit at reduced amounts relative to rice. The arid-grown species Setaria italica (C4) and Brachypodium distachyon (C3) were also found to accumulate chloroplastic phosphoenolpyruvate carboxylase. We identified a molecular signature associated with C4 photosynthesis in nutrient-replete, waterlogged conditions that is highly similar to those previously reported from C4 plants that grow in more arid conditions. We also identified a cohort of genes that have been subjected to a selective sweep associated with growth in paddy conditions. Overall, this approach highlights the value of using wild species such as weeds to identify adaptions to specific conditions associated with high-yielding crops in agriculture.

Description

Keywords

Chloroplasts, Crops, Agricultural, Echinochloa, Gene Expression Regulation, Plant, Oryza, Phosphoenolpyruvate Carboxylase, Photosynthesis, Plant Cells, Plant Proteins, Plant Weeds, Transcriptome

Journal Title

Plant Physiol

Conference Name

Journal ISSN

0032-0889
1532-2548

Volume Title

170

Publisher

Oxford University Press (OUP)
Sponsorship
Biotechnology and Biological Sciences Research Council (BB/I024445/1)
Bill & Melinda Gates Foundation (via International Rice Research Institute (IRRI)) (unknown)