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Turnip mosaic virus (TuMV), the only potyvirus known to infect brassicas, is a devastating virus threatening many economically important brassica crops, including cabbage, Chinese cabbage, oilseed rape and mustard. TuMV disease, which was first discovered in the United States, is now found worldwide, especially in Europe, Asia and North America. TuMV results in a yield loss of up to 70% and has a wide host range, infecting most cruciferous plants, as well as many non‐cruciferous species. This virus is also characterized by high pathotype diversity because of its highly variable genome structure and has been divided into 12 pathotypes. These characteristics, as well as its nonpersistent transmission mode by as many as 89 aphid species, mean the disease is difficult to prevent through traditional methods such as the application of chemicals, prompting researchers to seek host resistance for effective control. During the last decade, extensive studies have been conducted to investigate inheritance, mapping and cloning of the TuMV resistance genes, and several NB‐LRR‐ or eIF‐encoding loci with divergent molecular mechanisms have been uncovered. These studies have greatly facilitated resistance breeding for brassica crops and have advanced our understanding of virus−host interactions. [ABSTRACT FROM AUTHOR]

Main Conclusion: Gene co-expression network analysis of the heat-responsive core transcriptome in two contrasting Brassica rapa accessions reveals the main metabolic pathways, key modules and hub genes, are involved in long-term heat stress. Brassica rapa is a widely cultivated and economically important vegetable in Asia. High temperature is a common stress that severely impacts leaf head formation in B. rapa, resulting in reduced quality and production. The purpose of this study was thus to identify candidate heat tolerance genes by comparative transcriptome analysis of two contrasting B. rapa accessions in response to long-term heat stress. Two B. rapa accessions, '268' and '334', which showed significant differences in heat tolerance, were used for RNA sequencing analysis. We identified a total of 11,055 and 8921 differentially expressed genes (DEGs) in '268' and '334', respectively. Functional enrichment analyses of all of the identified DEGs, together with the genes identified from weighted gene co-expression network analyses (WGCNA), revealed that the autophagy pathway, glutathione metabolism, and ribosome biogenesis in eukaryotes were significantly up-regulated, whereas photosynthesis was down-regulated, in the heat resistance of B. rapa '268'. Furthermore, when B. rapa '334' was subjected to long-term high-temperature stress, heat stress caused significant changes in the expression of certain functional genes linked to protein processing in the endoplasmic reticulum and plant hormone signal transduction pathways. Autophagy-related genes might have been induced by persistent heat stress and remained high during recovery. Several hub genes like HSP17.6, HSP17.6B, HSP70-8, CLPB1, PAP1, PYR1, ADC2, and GSTF11 were discussed in this study, which may be potential candidates for further analyses of the response to long-term heat stress. These results should help elucidate the molecular mechanisms of heat stress adaptation in B. rapa.

Linking remote sensing information and ecohydrological models to improve understanding of terrestrial biosphere responses to climate and land use change has become the subject of increased interest due to the impacts of current global changes and the effect on the sustainability of human lifestyles. An application to Asia and Australasia (1982-2015) is presented, revealing the following results: (i) The broad distribution of regions with the enhanced vegetation greenness only follows the general pattern as for the whole, without obvious dependence on regional or climate fluxes ratios. That indicates a prevailing increasing greenness over land due to both the impacts of current global changes and the sustainability of human lifestyles; (ii) regions with vegetation greenness reduction reveal a unique distribution, concentrating in the water-limited domain due to the impacts of external (climatically "dry gets drier and wet gets wetter") and internal (anthropogenically increased evaporation) changes; (iii) the external changes of dryness diverge at the boundary separating energy from water-limited regimes, and the internal changes indicate large-scale afforestation and deforestation) that occur mainly in China and Russia due to a conservation program and illegal logging, respectively, and a massive conversion of tropical forest to industrial tree plantations in Southeast Asia, leading to an increased evaporation.