Plants can sustain various degrees of damage or compensate for tissue loss by regrowth without significant fitness costs. This tolerance to insect herbivory depends on the plant's developmental stage during which the damage is inflicted and on how much tissue is removed. Plant fitness correlates, that is, biomass and germination of seeds, were determined at different ontogenetic stages, vegetative, budding, or flowering stages of three annual brassicaceous species exposed to feeding by Pieris brassicae caterpillars at different intensities. Fitness costs decreased with progressive ontogenetic stage at which damage was inflicted. Feeding on meristem tissues on vegetative and budding plants limited the plant's ability to fully compensate for tissue loss, whereas feeding on flowers resulted in full compensation or overcompensation in Sinapis arvensis and Brassica nigra. Herbivory promoted germination of seeds in the following year, thereby causing a shift in relative contribution to the next year's generation at the expense of contributing to the long-lived seed bank. Herbivory intensity affected fitness correlates of B. nigra and to a lesser extent of Sisymbrium officinale, but not of S. arvensis, demonstrating that even closely related plant species can differ in their specific responses to herbivory and that these can differently affect reproductive output. In terms of fitness costs, annual plant species can be quite resilient to herbivory. However, the extent to which they tolerate tissue loss depends on the ontogenetic stage that is under attack. Seed persistence in the soil has been proposed as a bet-hedging strategy of short-lived species to increase long-term fitness. Herbivore-induced changes in seed germination can result in a shift in the relative contribution of seeds to the seed bank and next year's generation.

Sorghum [Sorghum bicolor (L.) Moench] grain yield is vulnerable to drought stress. Therefore, developing appropriate technologies to mitigate drought is essential. We hypothesize that inhibition of photosynthesis and reproductive success by drought in sorghum can be improved by enhanced osmolyte accumulation and antioxidant defence system by foliar application of nanoselenium. In this study, the ecotoxicity potential and the physiological basis of drought alleviation by nanoselenium were evaluated. Nanoselenium did not cause toxicity to soil, aquatic and terrestrial organisms up to 20 mg L-1.-1 . During drought, foliar application of nanoselenium at 20 mg L-1 reduced the transpiration rate (16 %) compared to water spray. The superoxide radical content (50 %), hydrogen peroxide content (35 %), and membrane damage (26 %) were reduced, indicating antioxidant activity was exerted by nanoselenium. In contrast, the leaf turgor potential (80 %), relative water content (17 %), reducing sugars (57 %), non-reducing sugars (11 %), and proline (35%) contents were increased by nanoselenium than water spray, indicating a higher tissue water content was maintained, which has increased the photosynthetic rate (26 %). Higher reproductive success in nanoselenium-sprayed plants under drought was associated with reproductive tissue morphology and an increased number of pollen grains attached to the stigma. Foliar application of nanoselenium at 20 mg L-1 increased seed-set percentage (21 %) and seed yield (26 %) under drought than control. A similar response was observed by foliar spray with sodium selenate. Overall, foliar application of nanoselenium at 20 mg L-1 improved the drought tolerance of sorghum by reducing the transpiration rate and increasing the antioxidant defense system. (c) 2024 SAAB. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cassytha filiformis is a hemiparasitic plant that causes severe effects in its host plants. Since this decade, this alien species has been increasing its distribution towards the coastal areas of the Peninsula of Yucatan, parasitizing shrub species that play a crucial role in the containment of soil erosion. Here we studied the current distribution of C. filiformis along the coastal dune in northern Yucatan, recording the frequency of parasitism and the identity of its host plants. In addition, we evaluated the effect of C. filiformis on the sexual reproductive success of the main host plants and the effect of host species identity on C. filiformi's reproductive success. We found that the distribution of C. filiformis occurs throughout the coastal dunes of Yucatan (covering approximate to 250 km), parasitizing 15 species. However, ca. 70% of C. filiformis plants occur on three common shrub species: Suriana maritima, Scaevola plumieri, and Tournefortia gnaphalodes. The frequency of parasitized plants by C. filiformis was not dependent on host plant abundance. Tournefortia gnaphalodes suffer a higher proportion of parasitism. The reproductive success of the three host plants was lower in the presence of the parasitic plant. On the other hand, C. filiformis showed higher reproductive success when parasitizing S. maritima. Our results suggest that C. filiformis has extensively invaded the Yucatan coastal dunes, significantly reducing the sexual reproduction of its host-plant species. Overall, our results suggest that C. filiformis has the potential to cause significant damage in the Yucatan coastal dune community.