No abstract

Planting patterns affect nitrogen (N), phosphorus (P), and potassium (K) acquisition and distribution in maize and soybean under intercropping conditions. Here we reveal that strip relay-intercropping increases the N, P, and K uptake and distribution across plant organs (root, straw, and seed) of maize and soybean, accelerates the dry-matter production of intercrop-species, and compensates the slight maize yield loss by considerably increasing the soybean yield. In a two-year experiment, soybean was planted with maize in different planting patterns (SI, 50:50 cm and SII, 40:160 cm) of relay-intercropping, both planting patterns were compared with sole cropping of maize (SM) and soybean (SS). As compared to SI, SII increased the N, P, and K accumulation in each organ of soybean by 20, 32, and 18 (root) %, 71, 61, and 76 (straw) %, and 68, 65, and 62 (seed) %, respectively, whereas decreased the N, P, and K accumulation in each organ of maize by 1, 4, and 8 (root) %, 1, 10, and 3 (straw) %, and 5, 10, and 8 (seed) %, respectively. Overall, in SII, relay-cropped soybean accumulated 91% of total nutrient uptake (TNU) of sole soybean plants, and relay-cropped maize accumulated 94% of TNU of sole maize plants.

Background: Heat and drought are serious threats for crop growth and development. As the sixth largest cereal crop in the world, pearl millet can not only be used for food and forage but also as a source of bioenergy. Pearl millet is highly tolerant to heat and drought. Given this, it is considered an ideal crop to study plant stress tolerance and can be used to identify heat-resistant genes. Results: In this study, we used Pacbio sequencing data as a reference sequence to analyze the Illumina data of pearl millet that had been subjected to heat and drought stress for 48 h. By summarizing previous studies, we found 26,299 new genes and 63,090 new transcripts, and the number of gene annotations increased by 20.18%. We identified 2792 transcription factors and 1223 transcriptional regulators. There were 318 TFs and 149 TRs differentially expressed under heat stress, and 315 TFs and 128 TRs were differentially expressed under drought stress. We used RNA sequencing to identify 6920 genes and 6484 genes differentially expressed under heat stress and drought stress, respectively. Conclusions: Through Pacbio sequencing, we have identified more new genes and new transcripts. On the other hand, comparing the differentially expressed genes under heat tolerance with the DEGs under drought stress, we found that even in the same pathway, pearl millet responds with a different protein.

No abstract

No abstract

Drought stress is a major limitation in enhancing agricultural productivity to fulfill the food demand for the world's population. Fertigation of plants with a variety of biochemicals is being used to create drought resistance in wheat; however, the previous work has been limited in addressing these issues in plants at different growth stages.Therefore, a greenhouse study was conducted to ameliorate the drought stress in two wheat varieties (Chakwal-50 and Faisalabad-2008) by foliar application of 24-epibrassinolide (EBL). It was evident that drought stress had a negative effect on the growth, photosynthesis, and yield of wheat plants. EBL significantly enhanced the plant growth both under optimal and drought conditions. EBL improved the plant height, spike length, and the dry weights of roots, shoots, and grains as compared to control. Furthermore, the foliar application of EBL positively enhanced the osmolyte accumulation, increased the amounts of photosynthetic pigments, and improved the gas exchange parameters. The EBL minimized the oxidative stress by reducing electrolyte leakage, malondialdehyde, and hydrogen peroxide contents whereas it enhanced the activities of antioxidant enzymes, such as catalase, superoxide dismutase, and peroxidase under drought stress. The EBL significantly improved the level of stress hormones, such as abscisic acid, indol acetic acid, and cytokinin under drought stress. The growth response of Chakwal-50 was higher than that of Faisalabad-2008 when exposed to EBL under drought stress. Overall, the EBL plays a major role in the enhancement of growth, biomass, yield, and decrease in oxidative damage in wheat under drought conditions, however; field investigations with different doses of EBL are needed before any further recommendation. | INTRODUCTIONFood security is a global issue for the development of sustainable agriculture. In the present scenario, the shortage of freshwater required for agriculture has created serious problems for the production of crops with better nutritional quality in near future (Ali et al., 2019a).

Drought stress is one of the most immense and permanent constraints in agriculture, which leads to a massive loss of crop productivity. However, little is known about the mitigation role of exogenously applied abscisic acid (ABA) and jasmonic acid (JA) in pearl millet (Pennisetum glaucum L.) under PEG-induced drought stress. Therefore, the current study investigated the putative role of exogenous ABA and JA in improving drought stress tolerance in pearl millet. Thirteen-day-old seedlings were exposed to six different treatments as follow; control (ck), PEG-600 (20%), JA (100 μM), ABA (100 μM), PEG+JA, and PEG+ABA, and data were collected at 7 and 14 days after treatment (DAT). Results showed that PEG decreased plant growth while the oxidative damage increased due to over production of H 2 O 2 and MDA content as a result of decreased activities of the antioxidative enzymes including APX, CAT, and SOD in the leaves. However, exogenous ABA and JA positively enhanced the growth profile of seedlings by improving chlorophyll and relative water content under PEG treatment. A significant improvement was observed in the plant defense system resulting from increased activities of antioxidative enzymes due to exogenous ABA and JA under PEG. Overall, the performance of JA was found better than ABA under PEGinduced drought stress, and future investigations are needed to explore the potential effects of these phytohormones on the long-term crop management and productivity under drought stress.

Planting arrangements affect radiation use efficiency (RUE) and competitiveness of intercrop species in intercropping systems. Here, we reveal that narrow‐wide‐row planting arrangement in maize‐soybean relay‐intercropping system increases the dry matter and competitiveness of soybean, increased the RUE of maize and soybean, and compensates the yield loss of maize by substantially increasing the yield of soybean. In this field study, maize was planted with soybean in different planting arrangements (P1, 20:180, P2, 40:160; P3, 60:140, and P4, 80:120) of relay intercropping, all the relay‐intercropping treatments were compared with sole crops of maize (SM) and soybean (SS). Results showed that P1 improved the total RUE 3.26 g/MJ (maize RUE + soybean RUE) of maize and soybean in relay‐intercropping system. Compared to P4, treatment P1 increased the soybean competition ratio (CR) values (by 55%) but reduced the maize CR values (by 29%), which in turn significantly improved the yield of soybean by maintaining the maize yield. Generally, in P1, soybean produced 82% of SS yield, and maize produced 88% of SM yield, and it achieved the land equivalent ratio of 1.7. These results suggest that by maintaining the appropriate planting distances between maize and soybean we can improve the competitiveness and yield of intercrop species in relay‐intercropping system.