Photosynthetic performance in jack bean [Canavalia ensiformis (L.) D.C.] under drought and after rehydration

Abstract

The effects of drought and rehydration on Canavalia ensiformis (L.) D.C. (jack bean) plants were evaluated using the following gas exchange parameters: net carbon assimilation rate (A), stomatal conductance (g s), Ci/Ca ratio and transpiration rate (E); chlorophyll a fluorescence: Fv/Fm and Fv/F0 ratio. The plants were cultivated under greenhouse conditions and after 30 days from the emergence, irrigation was suspended in the plants submitted to drought, to obtain the following predawn leaf water potential (psipd): -0.40 MPa (control), -1.00 MPa (moderate drought) and -2.30 Mpa (severe drought). Afterwards, the gas exchange and fluorescence analysis were initiated , and 24 h after rehydration the same analyses were repeated. The A, E, g s and Ci/Ca values decreased significantly under both drought treatments, without however changing the Fv/Fm and Fv/F0 values. The gas exchange parameters recovered after rehydration. It seems that drought affected photosynthesis by stomatal inhibition, as shown by the decreased gs and Ci/Ca values, besides the maintenance of PSII phtotochemical efficiency. The recovery of gas exchange after rehydration could be due to plant protection mechanisms.

Proteins responding to drought and high-temperature stress in Populus × euramericana cv. ‘74/76’

“…'74/76' growing in the drought and high-temperature stress Exposure of plants to drought and high-temperature stress led to a noticeable decrease in leaf Pn and Gs with decrease of w s . This finding has been reported in a diversity of plants (e.g., Siddique et al 1999;Horton et al 2001;Matos et al 2002;Flexas et al 2004;Zanella et al 2004). In our study, we also found that growth and survival of P. 9 euramericana cv.…”

Plant water relations and photosynthetic activity in three Tunisian chickpea (Cicer arietinum L.) genotypes subjected to drought

“…Although drought impaired photosynthesis, it did not damage the photosynthetic apparatus (Zanelle et al 2004). The reduction in photosynthesis in Myracrodruon urundeuva under drought conditions occurred primarily because of stomatal closure, rather than damage to PSII (Zanella et al 2004). In coffee plants under drought conditions partial maintenance of the quantum yield of PSII was observed despite photosynthesis suppression.…”

Fiber Residues from <i>Canavalia ensiformis</i> L. Seeds with Potential Use in Food Industry

“…The great adaptability of C. ensiformis to adverse conditions, mainly soil-related, has been of great relevance for the high protein production in regions inept for agriculture. Besides the seeds being a good source of protein and its use as livestock feed, this plant is also used in soil recovery in several countries [2]. In all legumes, the presence of anti-nutritional components may limit its use as food and feed.…”