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The Indo-China Peninsula lies in a tropical monsoon climate zone and is prone to extreme weather events, including droughts and floods. Against the backdrop of global warming, the frequent occurrences of extreme precipitation affect the typical growth and phenology of vegetation. Based on the Sen+Mann-Kendall method and grey correlation analysis, the temporal and spatial characteristics of vegetation phenology and extreme precipitation in the Indo-China Peninsula and their relationships are analyzed. Vegetation phenological indices are extracted from MCD12Q2 and include the start of the growing season (SGS), the end of the growing season (EGS), and the length of the growing season (LGS). Based on the rescaled range (R/S) analysis, the future trends of these three phenological indices are predicted. The results show the following: 1) Spatial and temporal distribution characteristics: From 2001 to 2018, the SGS and EGS in the eastern region occurred earlier than those in the western region, and LGS was related to vegetation type, lasting approximately 3-7 months in agricultural areas and around 8-9 months in other areas. Excluding the number of rainstorm days (R50), the spatial distribution characteristics of extreme precipitation index were similar to that of annual total precipitation (PRCPTOT), which was higher in the west and lower in the east; 2) Trend: The SGS and EGS show an advanced trend, while the LGS shows a shortened trend; PRCPTOT and daily precipitation intensity had no obvious changes, maximum daily precipitation, extremely heavy rainfall, and R50 show a downward trend, while moderate rain days, heavy rain days and continuous wet days show an upward trend; these demonstrate that the Indo-China Peninsula has fewer extremely strong precipitation events, increased moderate intensity extreme events, and longer duration of rainfall events; 3) Correlation: By comparing the grey correlation degree between phenological indices and extreme precipitation indices, the distribution of the main extreme precipitation indices were obtained and found to have similar and concentrated spatial distribution; the spatial characteristic shows that there was a close relation between vegetation phenology and regional climate; the Indo-China Peninsula is divided into three zones from north to south, and the main controlling factors are the absolute index, the relative index, and the persistence index, respectively; 4) Sustainability: Based on the coupling analysis of H index of phenological indices calculated by R/S method and the Sen+Mann-Kendall method, we found that the future trend of phenological indicators was delayed and opposite to the previous trend in most parts of the Indo-China Peninsula. It is necessary to further study the index system and refine extreme precipitation events to distinguish the effects of different events on vegetation phenology.

The COVID-19 pandemic, caused by SARS-CoV-2, demonstrated that zoonotic transmission of animal sarbecoviruses threatens human health but the determinants of transmission are incompletely understood. Here, we show that most spike (S) proteins of horseshoe bat and Malayan pangolin sarbecoviruses employ ACE2 for entry, with human and raccoon dog ACE2 exhibiting broad receptor activity. The insertion of a multibasic cleavage site into the S proteins increased entry into human lung cells driven by most S proteins tested, suggesting that acquisition of a multibasic cleavage site might increase infectivity of diverse animal sarbecoviruses for the human respiratory tract. In contrast, two bat sarbecovirus S proteins drove cell entry in an ACE2-independent, trypsin-dependent fashion and several ACE2-dependent S proteins could switch to the ACE2-independent entry pathway when exposed to trypsin. Several TMPRSS2-related cellular proteases but not the insertion of a multibasic cleavage site into the S protein allowed for ACE2-independent entry in the absence of trypsin and may support viral spread in the respiratory tract. Finally, the pan-sarbecovirus antibody S2H97 enhanced cell entry driven by two S proteins and this effect was reversed by trypsin while trypsin protected entry driven by a third S protein from neutralization by S2H97. Similarly, plasma from quadruple vaccinated individuals neutralized entry driven by all S proteins studied, and availability of the ACE2-independent, trypsin-dependent pathway reduced neutralization sensitivity. In sum, our study reports a pathway for entry into human cells that is ACE2-independent, can be supported by TMPRSS2-related proteases and may be associated with antibody evasion. Author summary: Bats host a wide range of coronaviruses, including those related to SARS-CoV-1 and SARS-CoV-2 (subgenus Sarbecovirus), but their ability to infect human cells remains poorly understood. Identifying sarbecoviruses with zoonotic potential and understanding the factors controlling their entry into human cells are crucial for risk assessment and antiviral development. In this study, we examined how bat sarbecovirus spike proteins facilitate entry into human cells and identified key host factors involved. Using pseudovirus particles, we show that several bat sarbecovirus spike proteins use human and animal ACE2 receptors for entry. Additionally, we confirm that some spike proteins utilize an ACE2-independent entry pathway requiring trypsin treatment and demonstrate that this process is controlled by the spike protein receptor binding domain. Furthermore, we reveal that a subset of ACE2-using bat sarbecovirus spike proteins can switch to ACE2-independent entry following trypsin exposure and show that certain human type II transmembrane serine proteases can substitute for trypsin, enabling ACE2-independent entry. Finally, we demonstrate that repeated COVID-19 vaccination generates cross-neutralizing activity against bat sarbecoviruses, though ACE2-independent entry reduces neutralization sensitivity. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic has caused immense losses in human lives and the global economy and posed significant challenges for global public health. As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, has evolved, thousands of single nucleotide variants (SNVs) have been identified across the viral genome. The roles of individual SNVs in the zoonotic origin, evolution, and transmission of SARS-CoV-2 have become the focus of many studies. This review summarizes recent comparative genomic analyses of SARS-CoV-2 and related coronaviruses (SC2r-CoVs) found in non-human animals, including delineation of SARS-CoV-2 lineages based on characteristic SNVs. We also discuss the current understanding of receptor-binding domain (RBD) evolution and characteristic mutations in variants of concern (VOCs) of SARS-CoV-2, as well as possible co-evolution between RBD and its receptor, angiotensin-converting enzyme 2 (ACE2). We propose that the interplay between SARS-CoV-2 and host RNA editing mechanisms might have partially resulted in the bias in nucleotide changes during SARS-CoV-2 evolution. Finally, we outline some current challenges, including difficulty in deciphering the complicated relationship between viral pathogenicity and infectivity of different variants, and monitoring transmission of SARS-CoV-2 between humans and animals as the pandemic progresses.