Combined effects of low light and water stress on Jatropha curcas L. promotes shoot growth and morphological adjustment

Abstract

Jatropha curcas (physic nut) is a plant with economic and pharmaceutical uses. Basic studies on the influence of environmental factors on the early development of J. curcas are important for improving farming techniques and increasing productivity. This study investigated the adjustments of J. curcas to the environmental factors of drought and light stress in order to determine which factors most strongly affect the allocation of biomass during early growth. Leaves, stems, and roots of young plants were sampled and leaf area was measured during January and June in 2011. Plants of J. curcas that were grown in shade and subjected to water stress showed higher biomass allocation to aerial parts (mainly stems), which can be explained as a strategy for maximizing carbon assimilation. The pattern of biomass allocation between aerial components and the root system changed in plants grown in shade. During June 2011, biomass in shade-grown J. curcas was preferentially allocated to stems, indicating long-term adjustment. The lower biomass allocation to the root system suggests reduced exploitation of soil water even when this resource is scarce. Thus, over the long term, growth of J. curcas may be compromised by the combined effects of light stress and water deficit.

Low Light Alters the Photosynthesis Process in Cigar Tobacco via Modulation of the Chlorophyll Content, Chlorophyll Fluorescence, and Gene Expression

“…Thinner leaves are more able to use low light efficiently by promoting SLA and decreasing SLW to maximize more carbon gain [28]. Other studies also find an increment in LA and SLA under low light stress [33,34], thus confirming the results of this study.…”

Differential response to water deficit stress and shade in two wheat (Triticum durum Desf.) cultivars: growth, water relations, osmolyte accumulation and photosynthetic pigments

“…In turn, shading improved Ψw even at the highest water deficit stress, which increased to -1.72 MPa and -1.93 MPa in Om Rabiaa and Maali cultivars, respectively. Carneiro et al, (2015) put forth the idea that the improved performance of shaded plants may also be related to better conditions both in terms of temperature and humidity. In addition, we showed a variation for drought tolerance between the two cultivars.…”

“…Drought and light are not independent either in space or in time and may cause a variety of plant responses which can be additive, synergistic or antagonistic. In semiarid and arid environments, shading with lower levels of water deficit and cooler temperatures may be an intermediate solution for reducing plant water stress (Nicolas et al, 2008), but it can also aggravate the growth of seedlings exposed to drought (Carneiro et al, 2015). Since water availability and light are often the main factors affecting productivity in dry regions, strategies to improve sustainable use of water and plant drought tolerance are of paramount interest (Dolferus, 2014).…”

Crop responses and management strategies under shade and drought stress

“…Some limited literature available (mostly on woody seedlings) regarding the effect of co-occurring shade and drought stress on plant growth is elicited below. Carneiro et al (2015) found that when shade (70%) grown Jatropha curcas plants were subjected to long-term water deficit conditions (irrigation withheld until signs of stress, i.e., leaf tipping and wilting became evident), the biomass allocated to roots was lowered by > 40% though the root length did not change. However, the leaf size of plants grown in co-occurring shade and drought stress was considerably greater than those grown under full sun and drought environment.…”